diff --git a/packages/connect/e2e/__fixtures__/cardanoSignTransaction.ts b/packages/connect/e2e/__fixtures__/cardanoSignTransaction.ts
index 55e0bb7ca3ed..50d87f491a35 100644
--- a/packages/connect/e2e/__fixtures__/cardanoSignTransaction.ts
+++ b/packages/connect/e2e/__fixtures__/cardanoSignTransaction.ts
@@ -696,6 +696,7 @@ export default {
                 protocolMagic: PROTOCOL_MAGICS.mainnet,
                 networkId: NETWORK_IDS.mainnet,
                 signingMode: CardanoTxSigningMode.ORDINARY_TRANSACTION,
+                use258Tag: false,
             },
             result: {
                 hash: 'e200b2c91f3493a1f3b9cfc8b6c141f70181741025e53941e9d57d22b1470c5c',
@@ -720,6 +721,43 @@ export default {
             legacyResults: [legacyResults.beforeConway],
         },
 
+        {
+            description: 'signStakeRegistrationConwayWith258TaggedSets',
+            params: {
+                inputs: [SAMPLE_INPUTS.shelley_input],
+                outputs: [SAMPLE_OUTPUTS.simple_shelley_output],
+                fee: FEE,
+                ttl: TTL,
+                certificates: [SAMPLE_CERTIFICATES.stake_registration_conway],
+                protocolMagic: PROTOCOL_MAGICS.mainnet,
+                networkId: NETWORK_IDS.mainnet,
+                signingMode: CardanoTxSigningMode.ORDINARY_TRANSACTION,
+                use258Tag: true,
+            },
+            result: {
+                // SHOULD FAIL
+                hash: 'e200b2c91f3493a1f3b9cfc8b6c141f70181741025e53941e9d57d22b1470c5c',
+                witnesses: [
+                    {
+                        type: 1,
+                        pubKey: '5d010cf16fdeff40955633d6c565f3844a288a24967cf6b76acbeb271b4f13c1',
+                        signature:
+                            '79a357517a08c7256b0fab1e93a92a477386f4c2d72cea7bc68527c0133c32472305f010350665d72e8017bb6c2080b5742680ce7700bbddda561c917f294a07',
+                        chainCode: null,
+                    },
+                    {
+                        type: 1,
+                        pubKey: 'bc65be1b0b9d7531778a1317c2aa6de936963c3f9ac7d5ee9e9eda25e0c97c5e',
+                        signature:
+                            'dca542910d0362fc22744e7a24732343db4e013495a7d9b47562886f09af8eb56ecaa105e20a9df3e4248fdab61dd91b6fb2a3bfc15d0d9a0442671c07e1ba02',
+                        chainCode: null,
+                    },
+                ],
+                auxiliaryDataSupplement: undefined,
+            },
+            legacyResults: [legacyResults.beforeConway],
+        },
+
         {
             description: 'signStakeRegistrationNoOutputs',
             params: {
@@ -2533,6 +2571,56 @@ export default {
             legacyResults: [legacyResults.beforePlutus],
         },
 
+        {
+            description: 'plutusWithRequiredSignersAndReferenceInputAnd258TaggedSets',
+            params: {
+                inputs: [SAMPLE_INPUTS.shelley_input],
+                outputs: [SAMPLE_OUTPUTS.simple_shelley_output],
+                fee: FEE,
+                ttl: TTL,
+                protocolMagic: PROTOCOL_MAGICS.mainnet,
+                networkId: NETWORK_IDS.mainnet,
+                signingMode: CardanoTxSigningMode.PLUTUS_TRANSACTION,
+                scriptDataHash: SCRIPT_DATA_HASH,
+                collateralInputs: [SAMPLE_INPUTS.shelley_input_2],
+                requiredSigners: [
+                    { keyPath: "m/1852'/1815'/0'/0/0" },
+                    { keyPath: "m/1854'/1815'/0'/0/0" },
+                    { keyHash: '3a7f09d3df4cf66a7399c2b05bfa234d5a29560c311fc5db4c490711' },
+                ],
+                referenceInput: [SAMPLE_INPUTS.plutus_input],
+                use258Tag: true,
+            },
+            result: {
+                hash: 'eee852948723773f059bbbc9f4378473e339a62ec518ac3aeb8ecdf27abf8581',
+                witnesses: [
+                    {
+                        type: 1,
+                        pubKey: '5d010cf16fdeff40955633d6c565f3844a288a24967cf6b76acbeb271b4f13c1',
+                        signature:
+                            'ccf25b4926d4ea953f9330196f881ec6974b3979a05fd679e846eb0fd90f5e5d64cdba51fad9354a50343a29c09dfda8177fd1717ca8d105c9d923a31071b909',
+                        chainCode: null,
+                    },
+                    {
+                        type: 1,
+                        pubKey: '36a8ef21d5b98fdf23a27325cf643deaac35e912c835e35037f23d1061ae5b16',
+                        signature:
+                            '39231ff0df125987c5a7583f307d74d3bdcb9702baafc8588aa16002d19d595725da64518603bb0617bfba851fe96f0cf75c19d75b0749443e09fdc8aebb4603',
+                        chainCode: null,
+                    },
+                    {
+                        type: 1,
+                        pubKey: 'b10be5c0d11ad8292bbe69e220ca0cfbe154610b3041a8e72f9d515c226ab3b1',
+                        signature:
+                            'e78e5a21c07ed5f613d01d20f9684a3b807b30ca211f69a2a0391ab3137d3b1260c51bdf08079e213e2487f3b8c36d6b42d7d15733113cf725ca3f162f030001',
+                        chainCode: null,
+                    },
+                ],
+                auxiliaryDataSupplement: undefined,
+            },
+            legacyResults: [legacyResults.beforeConway],
+        },
+
         {
             description: 'plutusWithManyWitnesses',
             params: {
diff --git a/packages/connect/src/api/cardano/api/cardanoSignTransaction.ts b/packages/connect/src/api/cardano/api/cardanoSignTransaction.ts
index d0d17250c213..b38bb4b432db 100644
--- a/packages/connect/src/api/cardano/api/cardanoSignTransaction.ts
+++ b/packages/connect/src/api/cardano/api/cardanoSignTransaction.ts
@@ -48,6 +48,7 @@ const CardanoSignTransactionFeatures = Object.freeze({
     Babbage: ['0', '2.5.2'],
     CIP36Registration: ['0', '2.5.3'],
     CIP36RegistrationExternalPaymentAddress: ['0', '2.5.4'],
+    Conway: ['0', '2.6.4'],
 });
 
 export type CardanoSignTransactionParams = {
@@ -73,6 +74,7 @@ export type CardanoSignTransactionParams = {
     additionalWitnessRequests: Path[];
     derivationType: PROTO.CardanoDerivationType;
     includeNetworkId?: boolean;
+    use258Tag?: boolean;
     unsignedTx?: { body: string; hash: string };
     testnet?: boolean;
 };
@@ -150,6 +152,7 @@ export default class CardanoSignTransaction extends AbstractMethod<
             { name: 'additionalWitnessRequests', type: 'array', allowEmpty: true },
             { name: 'derivationType', type: 'number' },
             { name: 'includeNetworkId', type: 'boolean' },
+            { name: 'use258Tag', type: 'boolean' },
             { name: 'unsignedTx', type: 'object' },
             { name: 'testnet', type: 'boolean' },
         ]);
@@ -258,6 +261,7 @@ export default class CardanoSignTransaction extends AbstractMethod<
                     ? payload.derivationType
                     : PROTO.CardanoDerivationType.ICARUS_TREZOR,
             includeNetworkId: payload.includeNetworkId,
+            use258Tag: payload.use258Tag,
             unsignedTx: 'unsignedTx' in payload ? payload.unsignedTx : undefined,
             testnet: 'testnet' in payload ? payload.testnet : undefined,
         };
@@ -290,6 +294,13 @@ export default class CardanoSignTransaction extends AbstractMethod<
             if (certificate.key_hash) {
                 this._ensureFeatureIsSupported('KeyHashStakeCredential');
             }
+            if (
+                certificate.type === PROTO.CardanoCertificateType.STAKE_REGISTRATION_CONWAY ||
+                certificate.type === PROTO.CardanoCertificateType.STAKE_DEREGISTRATION_CONWAY ||
+                certificate.type === PROTO.CardanoCertificateType.VOTE_DELEGATION
+            ) {
+                this._ensureFeatureIsSupported('Conway');
+            }
         });
 
         params.outputsWithData.forEach(({ output }) => {
@@ -319,6 +330,10 @@ export default class CardanoSignTransaction extends AbstractMethod<
             this._ensureFeatureIsSupported('NetworkIdInTxBody');
         }
 
+        if (params.use258Tag) {
+            this._ensureFeatureIsSupported('Conway');
+        }
+
         if (params.scriptDataHash) {
             this._ensureFeatureIsSupported('ScriptDataHash');
         }
@@ -397,6 +412,7 @@ export default class CardanoSignTransaction extends AbstractMethod<
             reference_inputs_count: this.params.referenceInputs.length,
             derivation_type: this.params.derivationType,
             include_network_id: this.params.includeNetworkId,
+            use_258_tag: this.params.use258Tag,
         };
 
         // init
diff --git a/packages/connect/src/types/api/__tests__/cardano.ts b/packages/connect/src/types/api/__tests__/cardano.ts
index caf38add058c..1ad886de9331 100644
--- a/packages/connect/src/types/api/__tests__/cardano.ts
+++ b/packages/connect/src/types/api/__tests__/cardano.ts
@@ -401,6 +401,7 @@ export const cardanoSignTransaction = async (api: TrezorConnect) => {
         networkId: 0,
         signingMode: CardanoTxSigningMode.ORDINARY_TRANSACTION,
         includeNetworkId: false,
+        use258Tag: false,
     });
 
     if (sign.success) {
diff --git a/packages/connect/src/types/api/cardano/index.ts b/packages/connect/src/types/api/cardano/index.ts
index d08c5cc07b37..d5d8a03e5f39 100644
--- a/packages/connect/src/types/api/cardano/index.ts
+++ b/packages/connect/src/types/api/cardano/index.ts
@@ -224,6 +224,7 @@ export interface CardanoSignTransaction {
     signingMode: PROTO.CardanoTxSigningMode;
     derivationType?: PROTO.CardanoDerivationType;
     includeNetworkId?: boolean;
+    use258Tag?: boolean;
 }
 
 export interface CardanoSignedTxWitness {