diff --git a/doc/release-notes-32406.md b/doc/release-notes-32406.md
new file mode 100644
index 00000000000..f1bbf188aff
--- /dev/null
+++ b/doc/release-notes-32406.md
@@ -0,0 +1,3 @@
+- `-datacarriersize` is increased to 100,000 which effectively uncaps the limit (as the maximum transaction size limit will be hit first). It can be overridden with -datacarriersize=83 to revert to the limit enforced in previous versions. Both `-datacarrier` and `-datacarriersize` options have been marked as deprecated and are expected to be removed in a future release. (#32406)
+
+- Multiple data carrier (OP_RETURN) outputs in a transaction are now permitted for relay and mining. The `-datacarriersize` limit applies to the aggregate size of the scriptPubKeys across all such outputs in a transaction, not including the scriptPubKey size itself. (#32406)
diff --git a/src/init.cpp b/src/init.cpp
index 831a7f5fc40..4817af5f01e 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -630,10 +630,10 @@ void SetupServerArgs(ArgsManager& argsman, bool can_listen_ipc)
     argsman.AddArg("-dustrelayfee=<amt>", strprintf("Fee rate (in %s/kvB) used to define dust, the value of an output such that it will cost more than its value in fees at this fee rate to spend it. (default: %s)", CURRENCY_UNIT, FormatMoney(DUST_RELAY_TX_FEE)), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-acceptstalefeeestimates", strprintf("Read fee estimates even if they are stale (%sdefault: %u) fee estimates are considered stale if they are %s hours old", "regtest only; ", DEFAULT_ACCEPT_STALE_FEE_ESTIMATES, Ticks<std::chrono::hours>(MAX_FILE_AGE)), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-bytespersigop", strprintf("Equivalent bytes per sigop in transactions for relay and mining (default: %u)", DEFAULT_BYTES_PER_SIGOP), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
-    argsman.AddArg("-datacarrier", strprintf("Relay and mine data carrier transactions (default: %u)", DEFAULT_ACCEPT_DATACARRIER), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
+    argsman.AddArg("-datacarrier", strprintf("(DEPRECATED) Relay and mine data carrier transactions (default: %u)", DEFAULT_ACCEPT_DATACARRIER), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarriersize",
-                   strprintf("Relay and mine transactions whose data-carrying raw scriptPubKey "
-                             "is of this size or less (default: %u)",
+                   strprintf("(DEPRECATED) Relay and mine transactions whose data-carrying raw scriptPubKeys in aggregate "
+                             "are of this size or less, allowing multiple outputs (default: %u)",
                              MAX_OP_RETURN_RELAY),
                    ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-permitbaremultisig", strprintf("Relay transactions creating non-P2SH multisig outputs (default: %u)", DEFAULT_PERMIT_BAREMULTISIG), ArgsManager::ALLOW_ANY,
@@ -875,6 +875,10 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         InitWarning(_("Option '-checkpoints' is set but checkpoints were removed. This option has no effect."));
     }
 
+    if (args.IsArgSet("-datacarriersize") || args.IsArgSet("-datacarrier")) {
+        InitWarning(_("Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version."));
+    }
+
     // Error if network-specific options (-addnode, -connect, etc) are
     // specified in default section of config file, but not overridden
     // on the command line or in this chain's section of the config file.
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp
index 32a31ea653c..fdc2fdb9cdf 100644
--- a/src/policy/policy.cpp
+++ b/src/policy/policy.cpp
@@ -76,7 +76,7 @@ std::vector<uint32_t> GetDust(const CTransaction& tx, CFeeRate dust_relay_rate)
     return dust_outputs;
 }
 
-bool IsStandard(const CScript& scriptPubKey, const std::optional<unsigned>& max_datacarrier_bytes, TxoutType& whichType)
+bool IsStandard(const CScript& scriptPubKey, TxoutType& whichType)
 {
     std::vector<std::vector<unsigned char> > vSolutions;
     whichType = Solver(scriptPubKey, vSolutions);
@@ -91,10 +91,6 @@ bool IsStandard(const CScript& scriptPubKey, const std::optional<unsigned>& max_
             return false;
         if (m < 1 || m > n)
             return false;
-    } else if (whichType == TxoutType::NULL_DATA) {
-        if (!max_datacarrier_bytes || scriptPubKey.size() > *max_datacarrier_bytes) {
-            return false;
-        }
     }
 
     return true;
@@ -137,17 +133,22 @@ bool IsStandardTx(const CTransaction& tx, const std::optional<unsigned>& max_dat
         }
     }
 
-    unsigned int nDataOut = 0;
+    unsigned int datacarrier_bytes_left = max_datacarrier_bytes.value_or(0);
     TxoutType whichType;
     for (const CTxOut& txout : tx.vout) {
-        if (!::IsStandard(txout.scriptPubKey, max_datacarrier_bytes, whichType)) {
+        if (!::IsStandard(txout.scriptPubKey, whichType)) {
             reason = "scriptpubkey";
             return false;
         }
 
-        if (whichType == TxoutType::NULL_DATA)
-            nDataOut++;
-        else if ((whichType == TxoutType::MULTISIG) && (!permit_bare_multisig)) {
+        if (whichType == TxoutType::NULL_DATA) {
+            unsigned int size = txout.scriptPubKey.size();
+            if (size > datacarrier_bytes_left) {
+                reason = "datacarrier";
+                return false;
+            }
+            datacarrier_bytes_left -= size;
+        } else if ((whichType == TxoutType::MULTISIG) && (!permit_bare_multisig)) {
             reason = "bare-multisig";
             return false;
         }
@@ -159,12 +160,6 @@ bool IsStandardTx(const CTransaction& tx, const std::optional<unsigned>& max_dat
         return false;
     }
 
-    // only one OP_RETURN txout is permitted
-    if (nDataOut > 1) {
-        reason = "multi-op-return";
-        return false;
-    }
-
     return true;
 }
 
diff --git a/src/policy/policy.h b/src/policy/policy.h
index 2151ec13dd0..e62efa02e3e 100644
--- a/src/policy/policy.h
+++ b/src/policy/policy.h
@@ -73,10 +73,9 @@ static constexpr unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT_KVB{101};
 /** Default for -datacarrier */
 static const bool DEFAULT_ACCEPT_DATACARRIER = true;
 /**
- * Default setting for -datacarriersize. 80 bytes of data, +1 for OP_RETURN,
- * +2 for the pushdata opcodes.
+ * Default setting for -datacarriersize in vbytes.
  */
-static const unsigned int MAX_OP_RETURN_RELAY = 83;
+static const unsigned int MAX_OP_RETURN_RELAY = MAX_STANDARD_TX_WEIGHT / WITNESS_SCALE_FACTOR;
 /**
  * An extra transaction can be added to a package, as long as it only has one
  * ancestor and is no larger than this. Not really any reason to make this
@@ -136,7 +135,7 @@ CAmount GetDustThreshold(const CTxOut& txout, const CFeeRate& dustRelayFee);
 
 bool IsDust(const CTxOut& txout, const CFeeRate& dustRelayFee);
 
-bool IsStandard(const CScript& scriptPubKey, const std::optional<unsigned>& max_datacarrier_bytes, TxoutType& whichType);
+bool IsStandard(const CScript& scriptPubKey, TxoutType& whichType);
 
 /** Get the vout index numbers of all dust outputs */
 std::vector<uint32_t> GetDust(const CTransaction& tx, CFeeRate dust_relay_rate);
diff --git a/src/test/fuzz/key.cpp b/src/test/fuzz/key.cpp
index d851e33adc5..e4bedff8b51 100644
--- a/src/test/fuzz/key.cpp
+++ b/src/test/fuzz/key.cpp
@@ -150,12 +150,12 @@ FUZZ_TARGET(key, .init = initialize_key)
         assert(fillable_signing_provider_pub.HaveKey(pubkey.GetID()));
 
         TxoutType which_type_tx_pubkey;
-        const bool is_standard_tx_pubkey = IsStandard(tx_pubkey_script, std::nullopt, which_type_tx_pubkey);
+        const bool is_standard_tx_pubkey = IsStandard(tx_pubkey_script, which_type_tx_pubkey);
         assert(is_standard_tx_pubkey);
         assert(which_type_tx_pubkey == TxoutType::PUBKEY);
 
         TxoutType which_type_tx_multisig;
-        const bool is_standard_tx_multisig = IsStandard(tx_multisig_script, std::nullopt, which_type_tx_multisig);
+        const bool is_standard_tx_multisig = IsStandard(tx_multisig_script, which_type_tx_multisig);
         assert(is_standard_tx_multisig);
         assert(which_type_tx_multisig == TxoutType::MULTISIG);
 
diff --git a/src/test/fuzz/script.cpp b/src/test/fuzz/script.cpp
index 07a49e039fb..9aa50559cbd 100644
--- a/src/test/fuzz/script.cpp
+++ b/src/test/fuzz/script.cpp
@@ -53,7 +53,7 @@ FUZZ_TARGET(script, .init = initialize_script)
     }
 
     TxoutType which_type;
-    bool is_standard_ret = IsStandard(script, std::nullopt, which_type);
+    bool is_standard_ret = IsStandard(script, which_type);
     if (!is_standard_ret) {
         assert(which_type == TxoutType::NONSTANDARD ||
                which_type == TxoutType::NULL_DATA ||
diff --git a/src/test/multisig_tests.cpp b/src/test/multisig_tests.cpp
index 29a73d03d25..b996f3cc061 100644
--- a/src/test/multisig_tests.cpp
+++ b/src/test/multisig_tests.cpp
@@ -144,7 +144,7 @@ BOOST_AUTO_TEST_CASE(multisig_IsStandard)
 
     const auto is_standard{[](const CScript& spk) {
         TxoutType type;
-        bool res{::IsStandard(spk, std::nullopt, type)};
+        bool res{::IsStandard(spk, type)};
         if (res) {
             BOOST_CHECK_EQUAL(type, TxoutType::MULTISIG);
         }
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index 7a60ea25d3f..54b3216a4c6 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -797,14 +797,14 @@ BOOST_AUTO_TEST_CASE(test_IsStandard)
     CKey key = GenerateRandomKey();
     t.vout[0].scriptPubKey = GetScriptForDestination(PKHash(key.GetPubKey()));
 
-    constexpr auto CheckIsStandard = [](const auto& t) {
+    constexpr auto CheckIsStandard = [](const auto& t, const unsigned int max_op_return_relay = MAX_OP_RETURN_RELAY) {
         std::string reason;
-        BOOST_CHECK(IsStandardTx(CTransaction{t}, MAX_OP_RETURN_RELAY, g_bare_multi, g_dust, reason));
+        BOOST_CHECK(IsStandardTx(CTransaction{t}, max_op_return_relay, g_bare_multi, g_dust, reason));
         BOOST_CHECK(reason.empty());
     };
-    constexpr auto CheckIsNotStandard = [](const auto& t, const std::string& reason_in) {
+    constexpr auto CheckIsNotStandard = [](const auto& t, const std::string& reason_in, const unsigned int max_op_return_relay = MAX_OP_RETURN_RELAY) {
         std::string reason;
-        BOOST_CHECK(!IsStandardTx(CTransaction{t}, MAX_OP_RETURN_RELAY, g_bare_multi, g_dust, reason));
+        BOOST_CHECK(!IsStandardTx(CTransaction{t}, max_op_return_relay, g_bare_multi, g_dust, reason));
         BOOST_CHECK_EQUAL(reason_in, reason);
     };
 
@@ -858,15 +858,13 @@ BOOST_AUTO_TEST_CASE(test_IsStandard)
     t.vout[0].scriptPubKey = CScript() << OP_1;
     CheckIsNotStandard(t, "scriptpubkey");
 
-    // MAX_OP_RETURN_RELAY-byte TxoutType::NULL_DATA (standard)
+    // Custom 83-byte TxoutType::NULL_DATA (standard with max_op_return_relay of 83)
     t.vout[0].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3804678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38"_hex;
-    BOOST_CHECK_EQUAL(MAX_OP_RETURN_RELAY, t.vout[0].scriptPubKey.size());
-    CheckIsStandard(t);
+    BOOST_CHECK_EQUAL(83, t.vout[0].scriptPubKey.size());
+    CheckIsStandard(t, /*max_op_return_relay=*/83);
 
-    // MAX_OP_RETURN_RELAY+1-byte TxoutType::NULL_DATA (non-standard)
-    t.vout[0].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3804678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3800"_hex;
-    BOOST_CHECK_EQUAL(MAX_OP_RETURN_RELAY + 1, t.vout[0].scriptPubKey.size());
-    CheckIsNotStandard(t, "scriptpubkey");
+    // Non-standard if max_op_return_relay datacarrier arg is one less
+    CheckIsNotStandard(t, "datacarrier", /*max_op_return_relay=*/82);
 
     // Data payload can be encoded in any way...
     t.vout[0].scriptPubKey = CScript() << OP_RETURN << ""_hex;
@@ -888,21 +886,28 @@ BOOST_AUTO_TEST_CASE(test_IsStandard)
     t.vout[0].scriptPubKey = CScript() << OP_RETURN;
     CheckIsStandard(t);
 
-    // Only one TxoutType::NULL_DATA permitted in all cases
+    // Multiple TxoutType::NULL_DATA are permitted
     t.vout.resize(2);
     t.vout[0].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38"_hex;
     t.vout[0].nValue = 0;
     t.vout[1].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38"_hex;
     t.vout[1].nValue = 0;
-    CheckIsNotStandard(t, "multi-op-return");
+    CheckIsStandard(t);
 
     t.vout[0].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38"_hex;
     t.vout[1].scriptPubKey = CScript() << OP_RETURN;
-    CheckIsNotStandard(t, "multi-op-return");
+    CheckIsStandard(t);
 
     t.vout[0].scriptPubKey = CScript() << OP_RETURN;
     t.vout[1].scriptPubKey = CScript() << OP_RETURN;
-    CheckIsNotStandard(t, "multi-op-return");
+    CheckIsStandard(t);
+
+    t.vout[0].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3804678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38"_hex;
+    t.vout[1].scriptPubKey = CScript() << OP_RETURN << "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef3804678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38"_hex;
+    const auto datacarrier_size = t.vout[0].scriptPubKey.size() + t.vout[1].scriptPubKey.size();
+    CheckIsStandard(t); // Default max relay should never trigger
+    CheckIsStandard(t, /*max_op_return_relay=*/datacarrier_size);
+    CheckIsNotStandard(t, "datacarrier", /*max_op_return_relay=*/datacarrier_size-1);
 
     // Check large scriptSig (non-standard if size is >1650 bytes)
     t.vout.resize(1);
diff --git a/test/functional/feature_blocksxor.py b/test/functional/feature_blocksxor.py
index 9824bf97151..ab5b0071b86 100755
--- a/test/functional/feature_blocksxor.py
+++ b/test/functional/feature_blocksxor.py
@@ -23,7 +23,6 @@ class BlocksXORTest(BitcoinTestFramework):
         self.extra_args = [[
             '-blocksxor=1',
             '-fastprune=1',             # use smaller block files
-            '-datacarriersize=100000',  # needed to pad transaction with MiniWallet
         ]]
 
     def run_test(self):
diff --git a/test/functional/feature_maxuploadtarget.py b/test/functional/feature_maxuploadtarget.py
index 1d7a7bfc55f..b72090b4363 100755
--- a/test/functional/feature_maxuploadtarget.py
+++ b/test/functional/feature_maxuploadtarget.py
@@ -51,7 +51,6 @@ class MaxUploadTest(BitcoinTestFramework):
         self.num_nodes = 1
         self.extra_args = [[
             f"-maxuploadtarget={UPLOAD_TARGET_MB}M",
-            "-datacarriersize=100000",
         ]]
         self.supports_cli = False
 
diff --git a/test/functional/mempool_accept.py b/test/functional/mempool_accept.py
index 9014ab260e1..d9c01161869 100755
--- a/test/functional/mempool_accept.py
+++ b/test/functional/mempool_accept.py
@@ -9,6 +9,7 @@ from decimal import Decimal
 import math
 
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.blocktools import MAX_STANDARD_TX_WEIGHT
 from test_framework.messages import (
     MAX_BIP125_RBF_SEQUENCE,
     COIN,
@@ -326,11 +327,52 @@ class MempoolAcceptanceTest(BitcoinTestFramework):
             result_expected=[{'txid': tx.rehash(), 'allowed': False, 'reject-reason': 'dust'}],
             rawtxs=[tx.serialize().hex()],
         )
+
+        # OP_RETURN followed by non-push
         tx = tx_from_hex(raw_tx_reference)
-        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b'\xff'])
-        tx.vout = [tx.vout[0]] * 2
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, OP_HASH160])
         self.check_mempool_result(
-            result_expected=[{'txid': tx.rehash(), 'allowed': False, 'reject-reason': 'multi-op-return'}],
+            result_expected=[{'txid': tx.rehash(), 'allowed': False, 'reject-reason': 'scriptpubkey'}],
+            rawtxs=[tx.serialize().hex()],
+        )
+
+        # Multiple OP_RETURN and more than 83 bytes, even if over MAX_SCRIPT_ELEMENT_SIZE
+        # are standard since v30
+        tx = tx_from_hex(raw_tx_reference)
+        tx.vout.append(CTxOut(0, CScript([OP_RETURN, b'\xff'])))
+        tx.vout.append(CTxOut(0, CScript([OP_RETURN, b'\xff' * 50000])))
+
+        self.check_mempool_result(
+            result_expected=[{'txid': tx.rehash(), 'allowed': True, 'vsize': tx.get_vsize(), 'fees': {'base': Decimal('0.05')}}],
+            rawtxs=[tx.serialize().hex()],
+            maxfeerate=0
+        )
+
+        self.log.info("A transaction with several OP_RETURN outputs.")
+        tx = tx_from_hex(raw_tx_reference)
+        op_return_count = 42
+        tx.vout[0].nValue = int(tx.vout[0].nValue / op_return_count)
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b'\xff'])
+        tx.vout = [tx.vout[0]] * op_return_count
+        self.check_mempool_result(
+            result_expected=[{"txid": tx.rehash(), "allowed": True, "vsize": tx.get_vsize(), "fees": {"base": Decimal("0.05000026")}}],
+            rawtxs=[tx.serialize().hex()],
+        )
+
+        self.log.info("A transaction with an OP_RETURN output that bumps into the max standardness tx size.")
+        tx = tx_from_hex(raw_tx_reference)
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN])
+        data_len = int(MAX_STANDARD_TX_WEIGHT / 4) - tx.get_vsize() - 5 - 4  # -5 for PUSHDATA4 and -4 for script size
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b"\xff" * (data_len)])
+        assert_equal(tx.get_vsize(), int(MAX_STANDARD_TX_WEIGHT / 4))
+        self.check_mempool_result(
+            result_expected=[{"txid": tx.rehash(), "allowed": True, "vsize": tx.get_vsize(), "fees": {"base": Decimal("0.1") - Decimal("0.05")}}],
+            rawtxs=[tx.serialize().hex()],
+        )
+        tx.vout[0].scriptPubKey = CScript([OP_RETURN, b"\xff" * (data_len + 1)])
+        assert_greater_than(tx.get_vsize(), int(MAX_STANDARD_TX_WEIGHT / 4))
+        self.check_mempool_result(
+            result_expected=[{"txid": tx.rehash(), "allowed": False, "reject-reason": "tx-size"}],
             rawtxs=[tx.serialize().hex()],
         )
 
diff --git a/test/functional/mempool_datacarrier.py b/test/functional/mempool_datacarrier.py
index 48e636caa22..8eab4ce6b28 100755
--- a/test/functional/mempool_datacarrier.py
+++ b/test/functional/mempool_datacarrier.py
@@ -18,14 +18,16 @@ from test_framework.wallet import MiniWallet
 
 from random import randbytes
 
+# The historical maximum, now used to test coverage
+CUSTOM_DATACARRIER_ARG = 83
 
 class DataCarrierTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 4
         self.extra_args = [
-            [],
-            ["-datacarrier=0"],
-            ["-datacarrier=1", f"-datacarriersize={MAX_OP_RETURN_RELAY - 1}"],
+            [], # default is uncapped
+            ["-datacarrier=0"], # no relay of datacarrier
+            ["-datacarrier=1", f"-datacarriersize={CUSTOM_DATACARRIER_ARG}"],
             ["-datacarrier=1", "-datacarriersize=2"],
         ]
 
@@ -41,32 +43,33 @@ class DataCarrierTest(BitcoinTestFramework):
             self.wallet.sendrawtransaction(from_node=node, tx_hex=tx_hex)
             assert tx.rehash() in node.getrawmempool(True), f'{tx_hex} not in mempool'
         else:
-            assert_raises_rpc_error(-26, "scriptpubkey", self.wallet.sendrawtransaction, from_node=node, tx_hex=tx_hex)
+            assert_raises_rpc_error(-26, "datacarrier", self.wallet.sendrawtransaction, from_node=node, tx_hex=tx_hex)
 
     def run_test(self):
         self.wallet = MiniWallet(self.nodes[0])
 
-        # By default, only 80 bytes are used for data (+1 for OP_RETURN, +2 for the pushdata opcodes).
-        default_size_data = randbytes(MAX_OP_RETURN_RELAY - 3)
-        too_long_data = randbytes(MAX_OP_RETURN_RELAY - 2)
-        small_data = randbytes(MAX_OP_RETURN_RELAY - 4)
+        # By default, any size is allowed.
+
+        # If it is custom set to 83, the historical value,
+        # only 80 bytes are used for data (+1 for OP_RETURN, +2 for the pushdata opcodes).
+        custom_size_data = randbytes(CUSTOM_DATACARRIER_ARG - 3)
+        too_long_data = randbytes(CUSTOM_DATACARRIER_ARG - 2)
+        extremely_long_data = randbytes(MAX_OP_RETURN_RELAY - 200)
         one_byte = randbytes(1)
         zero_bytes = randbytes(0)
 
-        self.log.info("Testing null data transaction with default -datacarrier and -datacarriersize values.")
-        self.test_null_data_transaction(node=self.nodes[0], data=default_size_data, success=True)
-
-        self.log.info("Testing a null data transaction larger than allowed by the default -datacarriersize value.")
-        self.test_null_data_transaction(node=self.nodes[0], data=too_long_data, success=False)
+        self.log.info("Testing a null data transaction succeeds for default arg regardless of size.")
+        self.test_null_data_transaction(node=self.nodes[0], data=too_long_data, success=True)
+        self.test_null_data_transaction(node=self.nodes[0], data=extremely_long_data, success=True)
 
         self.log.info("Testing a null data transaction with -datacarrier=false.")
-        self.test_null_data_transaction(node=self.nodes[1], data=default_size_data, success=False)
+        self.test_null_data_transaction(node=self.nodes[1], data=custom_size_data, success=False)
 
         self.log.info("Testing a null data transaction with a size larger than accepted by -datacarriersize.")
-        self.test_null_data_transaction(node=self.nodes[2], data=default_size_data, success=False)
+        self.test_null_data_transaction(node=self.nodes[2], data=too_long_data, success=False)
 
-        self.log.info("Testing a null data transaction with a size smaller than accepted by -datacarriersize.")
-        self.test_null_data_transaction(node=self.nodes[2], data=small_data, success=True)
+        self.log.info("Testing a null data transaction with a size equal to -datacarriersize.")
+        self.test_null_data_transaction(node=self.nodes[2], data=custom_size_data, success=True)
 
         self.log.info("Testing a null data transaction with no data.")
         self.test_null_data_transaction(node=self.nodes[0], data=None, success=True)
@@ -86,6 +89,17 @@ class DataCarrierTest(BitcoinTestFramework):
         self.test_null_data_transaction(node=self.nodes[2], data=one_byte, success=True)
         self.test_null_data_transaction(node=self.nodes[3], data=one_byte, success=False)
 
+        # Clean shutdown boilerplate due to deprecation
+        self.expected_stderr = [
+            "",  # node 0 has no deprecated options
+            "Warning: Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version.",
+            "Warning: Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version.",
+            "Warning: Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version.",
+        ]
+
+        for i in range(self.num_nodes):
+            self.stop_node(i, expected_stderr=self.expected_stderr[i])
+
 
 if __name__ == '__main__':
     DataCarrierTest(__file__).main()
diff --git a/test/functional/mempool_limit.py b/test/functional/mempool_limit.py
index 85d158d6111..791654a8c04 100755
--- a/test/functional/mempool_limit.py
+++ b/test/functional/mempool_limit.py
@@ -29,7 +29,6 @@ class MempoolLimitTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.num_nodes = 1
         self.extra_args = [[
-            "-datacarriersize=100000",
             "-maxmempool=5",
         ]]
         self.supports_cli = False
diff --git a/test/functional/mempool_package_limits.py b/test/functional/mempool_package_limits.py
index 3290ff43c49..63106f346f3 100755
--- a/test/functional/mempool_package_limits.py
+++ b/test/functional/mempool_package_limits.py
@@ -51,9 +51,6 @@ class MempoolPackageLimitsTest(BitcoinTestFramework):
         self.test_anc_count_limits()
         self.test_anc_count_limits_2()
         self.test_anc_count_limits_bushy()
-
-        # The node will accept (nonstandard) extra large OP_RETURN outputs
-        self.restart_node(0, extra_args=["-datacarriersize=100000"])
         self.test_anc_size_limits()
         self.test_desc_size_limits()
 
diff --git a/test/functional/mempool_package_rbf.py b/test/functional/mempool_package_rbf.py
index b638c5f512a..f760e427fe9 100755
--- a/test/functional/mempool_package_rbf.py
+++ b/test/functional/mempool_package_rbf.py
@@ -33,7 +33,6 @@ class PackageRBFTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         # Required for fill_mempool()
         self.extra_args = [[
-            "-datacarriersize=100000",
             "-maxmempool=5",
         ]] * self.num_nodes
 
diff --git a/test/functional/mempool_sigoplimit.py b/test/functional/mempool_sigoplimit.py
index 47df0c614ae..94c13f62a21 100755
--- a/test/functional/mempool_sigoplimit.py
+++ b/test/functional/mempool_sigoplimit.py
@@ -44,8 +44,6 @@ MAX_PUBKEYS_PER_MULTISIG = 20
 class BytesPerSigOpTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
-        # allow large datacarrier output to pad transactions
-        self.extra_args = [['-datacarriersize=100000']]
 
     def create_p2wsh_spending_tx(self, witness_script, output_script):
         """Create a 1-input-1-output P2WSH spending transaction with only the
@@ -139,7 +137,7 @@ class BytesPerSigOpTest(BitcoinTestFramework):
         self.log.info("Test a overly-large sigops-vbyte hits package limits")
         # Make a 2-transaction package which fails vbyte checks even though
         # separately they would work.
-        self.restart_node(0, extra_args=["-bytespersigop=5000","-permitbaremultisig=1"] + self.extra_args[0])
+        self.restart_node(0, extra_args=["-bytespersigop=5000","-permitbaremultisig=1"])
 
         def create_bare_multisig_tx(utxo_to_spend=None):
             _, pubkey = generate_keypair()
@@ -185,7 +183,7 @@ class BytesPerSigOpTest(BitcoinTestFramework):
             else:
                 bytespersigop_parameter = f"-bytespersigop={bytes_per_sigop}"
                 self.log.info(f"Test sigops limit setting {bytespersigop_parameter}...")
-                self.restart_node(0, extra_args=[bytespersigop_parameter] + self.extra_args[0])
+                self.restart_node(0, extra_args=[bytespersigop_parameter])
 
             for num_sigops in (69, 101, 142, 183, 222):
                 self.test_sigops_limit(bytes_per_sigop, num_sigops)
diff --git a/test/functional/mempool_truc.py b/test/functional/mempool_truc.py
index c2a65f9ade7..8a4f34e3669 100755
--- a/test/functional/mempool_truc.py
+++ b/test/functional/mempool_truc.py
@@ -49,7 +49,7 @@ class MempoolTRUC(BitcoinTestFramework):
         assert_equal(len(txids), len(mempool_contents))
         assert all([txid in txids for txid in mempool_contents])
 
-    @cleanup(extra_args=["-datacarriersize=20000"])
+    @cleanup()
     def test_truc_max_vsize(self):
         node = self.nodes[0]
         self.log.info("Test TRUC-specific maximum transaction vsize")
@@ -63,7 +63,7 @@ class MempoolTRUC(BitcoinTestFramework):
         tx_v2_heavy = self.wallet.send_self_transfer(from_node=node, target_vsize=TRUC_MAX_VSIZE + 1, version=2)
         self.check_mempool([tx_v2_heavy["txid"]])
 
-    @cleanup(extra_args=["-datacarriersize=1000"])
+    @cleanup()
     def test_truc_acceptance(self):
         node = self.nodes[0]
         self.log.info("Test a child of a TRUC transaction cannot be more than 1000vB")
@@ -160,7 +160,7 @@ class MempoolTRUC(BitcoinTestFramework):
         self.check_mempool([tx_v3_bip125_rbf_v2["txid"], tx_v3_parent["txid"], tx_v3_child["txid"]])
 
 
-    @cleanup(extra_args=["-datacarriersize=40000"])
+    @cleanup()
     def test_truc_reorg(self):
         node = self.nodes[0]
         self.log.info("Test that, during a reorg, TRUC rules are not enforced")
@@ -182,7 +182,7 @@ class MempoolTRUC(BitcoinTestFramework):
         node.reconsiderblock(block[0])
 
 
-    @cleanup(extra_args=["-limitdescendantsize=10", "-datacarriersize=40000"])
+    @cleanup(extra_args=["-limitdescendantsize=10"])
     def test_nondefault_package_limits(self):
         """
         Max standard tx size + TRUC rules imply the ancestor/descendant rules (at their default
@@ -215,7 +215,7 @@ class MempoolTRUC(BitcoinTestFramework):
         self.generate(node, 1)
 
         self.log.info("Test that a decreased limitancestorsize also applies to v3 parent")
-        self.restart_node(0, extra_args=["-limitancestorsize=10", "-datacarriersize=40000"])
+        self.restart_node(0, extra_args=["-limitancestorsize=10"])
         tx_v3_parent_large2 = self.wallet.send_self_transfer(
             from_node=node,
             target_vsize=parent_target_vsize,
@@ -235,7 +235,7 @@ class MempoolTRUC(BitcoinTestFramework):
         assert_raises_rpc_error(-26, "too-long-mempool-chain, exceeds ancestor size limit", node.sendrawtransaction, tx_v3_child_large2["hex"])
         self.check_mempool([tx_v3_parent_large2["txid"]])
 
-    @cleanup(extra_args=["-datacarriersize=1000"])
+    @cleanup()
     def test_truc_ancestors_package(self):
         self.log.info("Test that TRUC ancestor limits are checked within the package")
         node = self.nodes[0]
@@ -384,7 +384,7 @@ class MempoolTRUC(BitcoinTestFramework):
         assert_equal(result_package_cpfp["tx-results"][tx_sibling_3['wtxid']]['error'], expected_error_cpfp)
 
 
-    @cleanup(extra_args=["-datacarriersize=1000"])
+    @cleanup()
     def test_truc_package_inheritance(self):
         self.log.info("Test that TRUC inheritance is checked within package")
         node = self.nodes[0]
diff --git a/test/functional/mempool_updatefromblock.py b/test/functional/mempool_updatefromblock.py
index 46b69d67387..4ceeb3f149a 100755
--- a/test/functional/mempool_updatefromblock.py
+++ b/test/functional/mempool_updatefromblock.py
@@ -28,7 +28,7 @@ class MempoolUpdateFromBlockTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 1
         # Ancestor and descendant limits depend on transaction_graph_test requirements
-        self.extra_args = [['-limitdescendantsize=1000', '-limitancestorsize=1000', f'-limitancestorcount={CUSTOM_ANCESTOR_COUNT}', f'-limitdescendantcount={CUSTOM_DESCENDANT_COUNT}', '-datacarriersize=100000']]
+        self.extra_args = [['-limitdescendantsize=1000', '-limitancestorsize=1000', f'-limitancestorcount={CUSTOM_ANCESTOR_COUNT}', f'-limitdescendantcount={CUSTOM_DESCENDANT_COUNT}']]
 
     def create_empty_fork(self, fork_length):
         '''
diff --git a/test/functional/mining_basic.py b/test/functional/mining_basic.py
index 89f633cf7f0..12f1a4ddf5b 100755
--- a/test/functional/mining_basic.py
+++ b/test/functional/mining_basic.py
@@ -187,6 +187,9 @@ class MiningTest(BitcoinTestFramework):
             assert tx_below_min_feerate['txid'] not in block_template_txids
             assert tx_below_min_feerate['txid'] not in block_txids
 
+            # Restart node to clear mempool for the next test
+            self.restart_node(0)
+
     def test_timewarp(self):
         self.log.info("Test timewarp attack mitigation (BIP94)")
         node = self.nodes[0]
@@ -280,11 +283,9 @@ class MiningTest(BitcoinTestFramework):
     def test_block_max_weight(self):
         self.log.info("Testing default and custom -blockmaxweight startup options.")
 
-        # Restart the node to allow large transactions
         LARGE_TXS_COUNT = 10
         LARGE_VSIZE = int(((MAX_BLOCK_WEIGHT - DEFAULT_BLOCK_RESERVED_WEIGHT) / WITNESS_SCALE_FACTOR) / LARGE_TXS_COUNT)
         HIGH_FEERATE = Decimal("0.0003")
-        self.restart_node(0, extra_args=[f"-datacarriersize={LARGE_VSIZE}"])
 
         # Ensure the mempool is empty
         assert_equal(len(self.nodes[0].getrawmempool()), 0)
@@ -312,7 +313,7 @@ class MiningTest(BitcoinTestFramework):
         # Test block template creation with custom -blockmaxweight
         custom_block_weight = MAX_BLOCK_WEIGHT - 2000
         # Reducing the weight by 2000 units will prevent 1 large transaction from fitting into the block.
-        self.restart_node(0, extra_args=[f"-datacarriersize={LARGE_VSIZE}", f"-blockmaxweight={custom_block_weight}"])
+        self.restart_node(0, extra_args=[f"-blockmaxweight={custom_block_weight}"])
 
         self.log.info("Testing the block template with custom -blockmaxweight to include 9 large and 2 normal transactions.")
         self.verify_block_template(
@@ -322,7 +323,7 @@ class MiningTest(BitcoinTestFramework):
 
         # Ensure the block weight does not exceed the maximum
         self.log.info(f"Testing that the block weight will never exceed {MAX_BLOCK_WEIGHT - DEFAULT_BLOCK_RESERVED_WEIGHT}.")
-        self.restart_node(0, extra_args=[f"-datacarriersize={LARGE_VSIZE}", f"-blockmaxweight={MAX_BLOCK_WEIGHT}"])
+        self.restart_node(0, extra_args=[f"-blockmaxweight={MAX_BLOCK_WEIGHT}"])
         self.log.info("Sending 2 additional normal transactions to fill the mempool to the maximum block weight.")
         self.send_transactions(utxos[LARGE_TXS_COUNT + 2:], NORMAL_FEERATE, NORMAL_VSIZE)
         self.log.info(f"Testing that the mempool's weight matches the maximum block weight: {MAX_BLOCK_WEIGHT}.")
@@ -336,7 +337,7 @@ class MiningTest(BitcoinTestFramework):
 
         self.log.info("Test -blockreservedweight startup option.")
         # Lowering the -blockreservedweight by 4000 will allow for two more transactions.
-        self.restart_node(0, extra_args=[f"-datacarriersize={LARGE_VSIZE}", "-blockreservedweight=4000"])
+        self.restart_node(0, extra_args=["-blockreservedweight=4000"])
         self.verify_block_template(
             expected_tx_count=12,
             expected_weight=MAX_BLOCK_WEIGHT - 4000,
diff --git a/test/functional/mining_prioritisetransaction.py b/test/functional/mining_prioritisetransaction.py
index 2cb5d85b44f..a8646d49181 100755
--- a/test/functional/mining_prioritisetransaction.py
+++ b/test/functional/mining_prioritisetransaction.py
@@ -27,7 +27,6 @@ class PrioritiseTransactionTest(BitcoinTestFramework):
         self.num_nodes = 1
         self.extra_args = [[
             "-printpriority=1",
-            "-datacarriersize=100000",
         ]] * self.num_nodes
         self.supports_cli = False
 
diff --git a/test/functional/p2p_1p1c_network.py b/test/functional/p2p_1p1c_network.py
index e48e5b88b67..b098e4cf436 100755
--- a/test/functional/p2p_1p1c_network.py
+++ b/test/functional/p2p_1p1c_network.py
@@ -41,7 +41,6 @@ class PackageRelayTest(BitcoinTestFramework):
         # hugely speeds up the test, as it involves multiple hops of tx relay.
         self.noban_tx_relay = True
         self.extra_args = [[
-            "-datacarriersize=100000",
             "-maxmempool=5",
         ]] * self.num_nodes
         self.supports_cli = False
diff --git a/test/functional/p2p_opportunistic_1p1c.py b/test/functional/p2p_opportunistic_1p1c.py
index addb5027f37..0cdec4275fd 100755
--- a/test/functional/p2p_opportunistic_1p1c.py
+++ b/test/functional/p2p_opportunistic_1p1c.py
@@ -59,7 +59,6 @@ class PackageRelayTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.num_nodes = 1
         self.extra_args = [[
-            "-datacarriersize=100000",
             "-maxmempool=5",
         ]]
         self.supports_cli = False
diff --git a/test/functional/p2p_tx_download.py b/test/functional/p2p_tx_download.py
index 2b75c1193d1..3da781dee2e 100755
--- a/test/functional/p2p_tx_download.py
+++ b/test/functional/p2p_tx_download.py
@@ -68,7 +68,7 @@ class ConnectionType(Enum):
 class TxDownloadTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
-        self.extra_args= [['-datacarriersize=100000', '-maxmempool=5', '-persistmempool=0']] * self.num_nodes
+        self.extra_args= [['-maxmempool=5', '-persistmempool=0']] * self.num_nodes
 
     def test_tx_requests(self):
         self.log.info("Test that we request transactions from all our peers, eventually")
diff --git a/test/functional/rpc_packages.py b/test/functional/rpc_packages.py
index a2f9210f94d..119268213f4 100755
--- a/test/functional/rpc_packages.py
+++ b/test/functional/rpc_packages.py
@@ -438,7 +438,6 @@ class RPCPackagesTest(BitcoinTestFramework):
         # but child is too high fee
         # Lower mempool limit to make it easier to fill_mempool
         self.restart_node(0, extra_args=[
-            "-datacarriersize=100000",
             "-maxmempool=5",
             "-persistmempool=0",
         ])
@@ -467,7 +466,7 @@ class RPCPackagesTest(BitcoinTestFramework):
         assert parent["txid"] not in node.getrawmempool()
         assert child["txid"] not in node.getrawmempool()
 
-        # Reset maxmempool, datacarriersize, reset dynamic mempool minimum feerate, and empty mempool.
+        # Reset maxmempool, reset dynamic mempool minimum feerate, and empty mempool.
         self.restart_node(0)
         self.wallet.rescan_utxos()
 
diff --git a/test/functional/test_framework/mempool_util.py b/test/functional/test_framework/mempool_util.py
index 0e9c821e2ea..ef30b31b249 100644
--- a/test/functional/test_framework/mempool_util.py
+++ b/test/functional/test_framework/mempool_util.py
@@ -41,7 +41,7 @@ def fill_mempool(test_framework, node, *, tx_sync_fun=None):
     """Fill mempool until eviction.
 
     Allows for simpler testing of scenarios with floating mempoolminfee > minrelay
-    Requires -datacarriersize=100000 and -maxmempool=5 and assumes -minrelaytxfee
+    Requires -maxmempool=5 and assumes -minrelaytxfee
     is 1 sat/vbyte.
     To avoid unintentional tx dependencies, the mempool filling txs are created with a
     tagged ephemeral miniwallet instance.
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index e6f72f43b54..5549d8f753c 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -73,8 +73,10 @@ WITNESS_SCALE_FACTOR = 4
 DEFAULT_ANCESTOR_LIMIT = 25    # default max number of in-mempool ancestors
 DEFAULT_DESCENDANT_LIMIT = 25  # default max number of in-mempool descendants
 
-# Default setting for -datacarriersize. 80 bytes of data, +1 for OP_RETURN, +2 for the pushdata opcodes.
-MAX_OP_RETURN_RELAY = 83
+
+# Default setting for -datacarriersize.
+MAX_OP_RETURN_RELAY = 100_000
+
 
 DEFAULT_MEMPOOL_EXPIRY_HOURS = 336  # hours