diff --git a/docs/node-configuration.md b/docs/node-configuration.md
index 9120be64d2..bae794d7d5 100644
--- a/docs/node-configuration.md
+++ b/docs/node-configuration.md
@@ -341,7 +341,7 @@ protocol-related settings described in the table below.
 | MaxValidUntilBlockIncrement | `uint32` | `5760` | Upper height increment limit for transaction's ValidUntilBlock field value relative to the current blockchain height, exceeding which a transaction will fail validation. It is set to estimated daily number of blocks with 15s interval by default. |
 | MemPoolSize | `int` | `50000` | Size of the node's memory pool where transactions are stored before they are added to block. |
 | P2PNotaryRequestPayloadPoolSize | `int` | `1000` | Size of the node's P2P Notary request payloads memory pool where P2P Notary requests are stored before main or fallback transaction is completed and added to the chain.<br>This option is valid only if `P2PSigExtensions` are enabled. | Not supported by the C# node, thus may affect heterogeneous networks functionality. |
-| P2PSigExtensions | `bool` | `false` | Enables following additional Notary service related logic:<br>• Transaction attribute `NotaryAssisted`<br>• Network payload of the `P2PNotaryRequest` type<br>• Notary node module | Not supported by the C# node, thus may affect heterogeneous networks functionality. |
+| P2PSigExtensions | `bool` | `false` | Enables following additional Notary service related logic:<br>• Network payload of the `P2PNotaryRequest` type<br>• Notary node module | Not supported by the C# node, thus may affect heterogeneous networks functionality. |
 | P2PStateExchangeExtensions | `bool` | `false` | Enables the following P2P MPT state data exchange logic: <br>• `StateSyncInterval` protocol setting <br>• P2P commands `GetMPTDataCMD` and `MPTDataCMD` | Not supported by the C# node, thus may affect heterogeneous networks functionality. Can be supported either on MPT-complete node (`KeepOnlyLatestState`=`false`) or on light GC-enabled node (`RemoveUntraceableBlocks=true`) in which case `KeepOnlyLatestState` setting doesn't change the behavior, an appropriate set of MPTs is always stored (see `RemoveUntraceableBlocks`). |
 | ReservedAttributes | `bool` | `false` | Allows to have reserved attributes range for experimental or private purposes. |
 | SeedList | `[]string` | [] | List of initial nodes addresses used to establish connectivity. |
diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index c67ee5e430..8190ff6555 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -2697,8 +2697,8 @@ func (bc *Blockchain) verifyTxAttributes(d *dao.Simple, tx *transaction.Transact
 				return fmt.Errorf("%w: conflicting transaction %s is already on chain", ErrInvalidAttribute, conflicts.Hash.StringLE())
 			}
 		case transaction.NotaryAssistedT:
-			if !bc.config.P2PSigExtensions {
-				return fmt.Errorf("%w: NotaryAssisted attribute was found, but P2PSigExtensions are disabled", ErrInvalidAttribute)
+			if !bc.isHardforkEnabled(&transaction.NotaryAssistedActivation, bc.BlockHeight()) {
+				return fmt.Errorf("%w: NotaryAssisted attribute was found, but %s is not active yet", ErrInvalidAttribute, transaction.NotaryAssistedActivation)
 			}
 			if !tx.HasSigner(nativehashes.Notary) {
 				return fmt.Errorf("%w: NotaryAssisted attribute was found, but transaction is not signed by the Notary native contract", ErrInvalidAttribute)
diff --git a/pkg/core/blockchain_neotest_test.go b/pkg/core/blockchain_neotest_test.go
index e6dabb5b41..482ec7b95e 100644
--- a/pkg/core/blockchain_neotest_test.go
+++ b/pkg/core/blockchain_neotest_test.go
@@ -2057,7 +2057,12 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 			}
 			t.Run("Disabled", func(t *testing.T) {
 				bcBad, validatorBad, committeeBad := chain.NewMultiWithCustomConfig(t, func(c *config.Blockchain) {
-					c.P2PSigExtensions = false
+					c.P2PSigExtensions = true
+					c.Hardforks = map[string]uint32{
+						config.HFAspidochelone.String(): 0,
+						config.HFBasilisk.String():      0,
+						config.HFCockatrice.String():    0,
+					}
 					c.ReservedAttributes = false
 				})
 				eBad := neotest.NewExecutor(t, bcBad, validatorBad, committeeBad)
@@ -2069,7 +2074,7 @@ func TestBlockchain_VerifyTx(t *testing.T) {
 				eBad.SignTx(t, tx, 1_0000_0000, eBad.Committee)
 				err := bcBad.VerifyTx(tx)
 				require.Error(t, err)
-				require.True(t, strings.Contains(err.Error(), "invalid attribute: NotaryAssisted attribute was found, but P2PSigExtensions are disabled"))
+				require.True(t, strings.Contains(err.Error(), "invalid attribute: NotaryAssisted attribute was found, but Echidna is not active yet"))
 			})
 			t.Run("Enabled, insufficient network fee", func(t *testing.T) {
 				tx := getNotaryAssistedTx(e, 1, 0)
diff --git a/pkg/core/native/contract.go b/pkg/core/native/contract.go
index b0bd92b958..3949062518 100644
--- a/pkg/core/native/contract.go
+++ b/pkg/core/native/contract.go
@@ -72,9 +72,9 @@ func NewContracts(cfg config.ProtocolConfiguration) *Contracts {
 	cs.Ledger = ledger
 	cs.Contracts = append(cs.Contracts, ledger)
 
-	gas := newGAS(int64(cfg.InitialGASSupply), cfg.P2PSigExtensions)
+	gas := newGAS(int64(cfg.InitialGASSupply))
 	neo := newNEO(cfg)
-	policy := newPolicy(cfg.P2PSigExtensions)
+	policy := newPolicy()
 	neo.GAS = gas
 	neo.Policy = policy
 	gas.NEO = neo
diff --git a/pkg/core/native/management_test.go b/pkg/core/native/management_test.go
index 73859507b1..df10d4b868 100644
--- a/pkg/core/native/management_test.go
+++ b/pkg/core/native/management_test.go
@@ -17,7 +17,7 @@ import (
 
 func TestDeployGetUpdateDestroyContract(t *testing.T) {
 	mgmt := newManagement()
-	mgmt.Policy = newPolicy(false)
+	mgmt.Policy = newPolicy()
 	d := dao.NewSimple(storage.NewMemoryStore(), false)
 	ic := &interop.Context{DAO: d}
 	err := mgmt.Initialize(ic, nil, nil)
@@ -95,7 +95,7 @@ func TestManagement_Initialize(t *testing.T) {
 
 func TestManagement_GetNEP17Contracts(t *testing.T) {
 	mgmt := newManagement()
-	mgmt.Policy = newPolicy(false)
+	mgmt.Policy = newPolicy()
 	d := dao.NewSimple(storage.NewMemoryStore(), false)
 	err := mgmt.Initialize(&interop.Context{DAO: d}, nil, nil)
 	require.NoError(t, err)
diff --git a/pkg/core/native/native_gas.go b/pkg/core/native/native_gas.go
index 92f1aed7fb..7cfe34bce1 100644
--- a/pkg/core/native/native_gas.go
+++ b/pkg/core/native/native_gas.go
@@ -22,8 +22,7 @@ type GAS struct {
 	NEO    *NEO
 	Policy *Policy
 
-	initialSupply           int64
-	p2pSigExtensionsEnabled bool
+	initialSupply int64
 }
 
 const gasContractID = -6
@@ -32,10 +31,9 @@ const gasContractID = -6
 const GASFactor = NEOTotalSupply
 
 // newGAS returns GAS native contract.
-func newGAS(init int64, p2pSigExtensionsEnabled bool) *GAS {
+func newGAS(init int64) *GAS {
 	g := &GAS{
-		initialSupply:           init,
-		p2pSigExtensionsEnabled: p2pSigExtensionsEnabled,
+		initialSupply: init,
 	}
 	defer g.BuildHFSpecificMD(g.ActiveIn())
 
@@ -122,14 +120,12 @@ func (g *GAS) OnPersist(ic *interop.Context) error {
 	var netFee int64
 	for _, tx := range ic.Block.Transactions {
 		netFee += tx.NetworkFee
-		if g.p2pSigExtensionsEnabled {
-			// Reward for NotaryAssisted attribute will be minted to designated notary nodes
-			// by Notary contract.
-			attrs := tx.GetAttributes(transaction.NotaryAssistedT)
-			if len(attrs) != 0 {
-				na := attrs[0].Value.(*transaction.NotaryAssisted)
-				netFee -= (int64(na.NKeys) + 1) * g.Policy.GetAttributeFeeInternal(ic.DAO, transaction.NotaryAssistedT)
-			}
+		// Reward for NotaryAssisted attribute will be minted to designated notary nodes
+		// by Notary contract.
+		attrs := tx.GetAttributes(transaction.NotaryAssistedT)
+		if len(attrs) != 0 {
+			na := attrs[0].Value.(*transaction.NotaryAssisted)
+			netFee -= (int64(na.NKeys) + 1) * g.Policy.GetAttributeFeeInternal(ic.DAO, transaction.NotaryAssistedT)
 		}
 	}
 	g.mint(ic, primary, big.NewInt(int64(netFee)), false)
diff --git a/pkg/core/native/native_test/management_test.go b/pkg/core/native/native_test/management_test.go
index 9adc7e5c5b..498eb19271 100644
--- a/pkg/core/native/native_test/management_test.go
+++ b/pkg/core/native/native_test/management_test.go
@@ -58,6 +58,7 @@ var (
 	// under assumption that hardforks from Aspidochelone to Echidna (included) are enabled.
 	echidnaCSS = map[string]string{
 		nativenames.Notary: `{"id":-10,"hash":"0xc1e14f19c3e60d0b9244d06dd7ba9b113135ec3b","nef":{"magic":860243278,"compiler":"neo-core-v3.0","source":"","tokens":[],"script":"EEEa93tnQBBBGvd7Z0AQQRr3e2dAEEEa93tnQBBBGvd7Z0AQQRr3e2dAEEEa93tnQBBBGvd7Z0A=","checksum":1110259869},"manifest":{"name":"Notary","abi":{"methods":[{"name":"balanceOf","offset":0,"parameters":[{"name":"addr","type":"Hash160"}],"returntype":"Integer","safe":true},{"name":"expirationOf","offset":7,"parameters":[{"name":"addr","type":"Hash160"}],"returntype":"Integer","safe":true},{"name":"getMaxNotValidBeforeDelta","offset":14,"parameters":[],"returntype":"Integer","safe":true},{"name":"lockDepositUntil","offset":21,"parameters":[{"name":"address","type":"Hash160"},{"name":"till","type":"Integer"}],"returntype":"Boolean","safe":false},{"name":"onNEP17Payment","offset":28,"parameters":[{"name":"from","type":"Hash160"},{"name":"amount","type":"Integer"},{"name":"data","type":"Any"}],"returntype":"Void","safe":false},{"name":"setMaxNotValidBeforeDelta","offset":35,"parameters":[{"name":"value","type":"Integer"}],"returntype":"Void","safe":false},{"name":"verify","offset":42,"parameters":[{"name":"signature","type":"Signature"}],"returntype":"Boolean","safe":true},{"name":"withdraw","offset":49,"parameters":[{"name":"from","type":"Hash160"},{"name":"to","type":"Hash160"}],"returntype":"Boolean","safe":false}],"events":[]},"features":{},"groups":[],"permissions":[{"contract":"*","methods":"*"}],"supportedstandards":[],"trusts":[],"extra":null},"updatecounter":0}`,
+		nativenames.Policy: `{"id":-7,"hash":"0xcc5e4edd9f5f8dba8bb65734541df7a1c081c67b","nef":{"magic":860243278,"compiler":"neo-core-v3.0","source":"","tokens":[],"script":"EEEa93tnQBBBGvd7Z0AQQRr3e2dAEEEa93tnQBBBGvd7Z0AQQRr3e2dAEEEa93tnQBBBGvd7Z0AQQRr3e2dAEEEa93tnQBBBGvd7Z0A=","checksum":1094259016},"manifest":{"name":"PolicyContract","abi":{"methods":[{"name":"blockAccount","offset":0,"parameters":[{"name":"account","type":"Hash160"}],"returntype":"Boolean","safe":false},{"name":"getAttributeFee","offset":7,"parameters":[{"name":"attributeType","type":"Integer"}],"returntype":"Integer","safe":true},{"name":"getExecFeeFactor","offset":14,"parameters":[],"returntype":"Integer","safe":true},{"name":"getFeePerByte","offset":21,"parameters":[],"returntype":"Integer","safe":true},{"name":"getStoragePrice","offset":28,"parameters":[],"returntype":"Integer","safe":true},{"name":"isBlocked","offset":35,"parameters":[{"name":"account","type":"Hash160"}],"returntype":"Boolean","safe":true},{"name":"setAttributeFee","offset":42,"parameters":[{"name":"attributeType","type":"Integer"},{"name":"value","type":"Integer"}],"returntype":"Void","safe":false},{"name":"setExecFeeFactor","offset":49,"parameters":[{"name":"value","type":"Integer"}],"returntype":"Void","safe":false},{"name":"setFeePerByte","offset":56,"parameters":[{"name":"value","type":"Integer"}],"returntype":"Void","safe":false},{"name":"setStoragePrice","offset":63,"parameters":[{"name":"value","type":"Integer"}],"returntype":"Void","safe":false},{"name":"unblockAccount","offset":70,"parameters":[{"name":"account","type":"Hash160"}],"returntype":"Boolean","safe":false}],"events":[]},"features":{},"groups":[],"permissions":[{"contract":"*","methods":"*"}],"supportedstandards":[],"trusts":[],"extra":null},"updatecounter":0}`,
 	}
 )
 
@@ -255,6 +256,13 @@ func TestManagement_NativeDeployUpdateNotifications(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, 1, len(aer))
 	expected = expected[:0]
+	expected = append(expected, state.NotificationEvent{
+		ScriptHash: nativehashes.ContractManagement,
+		Name:       "Update",
+		Item: stackitem.NewArray([]stackitem.Item{
+			stackitem.Make(nativehashes.PolicyContract),
+		}),
+	})
 	expected = append(expected, state.NotificationEvent{
 		ScriptHash: nativehashes.ContractManagement,
 		Name:       "Deploy",
diff --git a/pkg/core/native/policy.go b/pkg/core/native/policy.go
index 0591fe7b44..a8a823639e 100644
--- a/pkg/core/native/policy.go
+++ b/pkg/core/native/policy.go
@@ -63,9 +63,6 @@ var (
 type Policy struct {
 	interop.ContractMD
 	NEO *NEO
-
-	// p2pSigExtensionsEnabled defines whether the P2P signature extensions logic is relevant.
-	p2pSigExtensionsEnabled bool
 }
 
 type PolicyCache struct {
@@ -100,11 +97,8 @@ func copyPolicyCache(src, dst *PolicyCache) {
 }
 
 // newPolicy returns Policy native contract.
-func newPolicy(p2pSigExtensionsEnabled bool) *Policy {
-	p := &Policy{
-		ContractMD:              *interop.NewContractMD(nativenames.Policy, policyContractID),
-		p2pSigExtensionsEnabled: p2pSigExtensionsEnabled,
-	}
+func newPolicy() *Policy {
+	p := &Policy{ContractMD: *interop.NewContractMD(nativenames.Policy, policyContractID)}
 	defer p.BuildHFSpecificMD(p.ActiveIn())
 
 	desc := newDescriptor("getFeePerByte", smartcontract.IntegerType)
@@ -136,13 +130,24 @@ func newPolicy(p2pSigExtensionsEnabled bool) *Policy {
 
 	desc = newDescriptor("getAttributeFee", smartcontract.IntegerType,
 		manifest.NewParameter("attributeType", smartcontract.IntegerType))
-	md = newMethodAndPrice(p.getAttributeFee, 1<<15, callflag.ReadStates)
+	md = newMethodAndPrice(p.getAttributeFeeV0, 1<<15, callflag.ReadStates, config.HFDefault, transaction.NotaryAssistedActivation)
+	p.AddMethod(md, desc)
+
+	desc = newDescriptor("getAttributeFee", smartcontract.IntegerType,
+		manifest.NewParameter("attributeType", smartcontract.IntegerType))
+	md = newMethodAndPrice(p.getAttributeFeeV1, 1<<15, callflag.ReadStates, transaction.NotaryAssistedActivation)
 	p.AddMethod(md, desc)
 
 	desc = newDescriptor("setAttributeFee", smartcontract.VoidType,
 		manifest.NewParameter("attributeType", smartcontract.IntegerType),
 		manifest.NewParameter("value", smartcontract.IntegerType))
-	md = newMethodAndPrice(p.setAttributeFee, 1<<15, callflag.States)
+	md = newMethodAndPrice(p.setAttributeFeeV0, 1<<15, callflag.States, config.HFDefault, transaction.NotaryAssistedActivation)
+	p.AddMethod(md, desc)
+
+	desc = newDescriptor("setAttributeFee", smartcontract.VoidType,
+		manifest.NewParameter("attributeType", smartcontract.IntegerType),
+		manifest.NewParameter("value", smartcontract.IntegerType))
+	md = newMethodAndPrice(p.setAttributeFeeV1, 1<<15, callflag.States, transaction.NotaryAssistedActivation)
 	p.AddMethod(md, desc)
 
 	desc = newDescriptor("setFeePerByte", smartcontract.VoidType,
@@ -170,27 +175,27 @@ func (p *Policy) Metadata() *interop.ContractMD {
 
 // Initialize initializes Policy native contract and implements the Contract interface.
 func (p *Policy) Initialize(ic *interop.Context, hf *config.Hardfork, newMD *interop.HFSpecificContractMD) error {
-	if hf != p.ActiveIn() {
-		return nil
-	}
-
-	setIntWithKey(p.ID, ic.DAO, feePerByteKey, defaultFeePerByte)
-	setIntWithKey(p.ID, ic.DAO, execFeeFactorKey, defaultExecFeeFactor)
-	setIntWithKey(p.ID, ic.DAO, storagePriceKey, DefaultStoragePrice)
-
-	cache := &PolicyCache{
-		execFeeFactor:      defaultExecFeeFactor,
-		feePerByte:         defaultFeePerByte,
-		maxVerificationGas: defaultMaxVerificationGas,
-		storagePrice:       DefaultStoragePrice,
-		attributeFee:       map[transaction.AttrType]uint32{},
-		blockedAccounts:    make([]util.Uint160, 0),
+	if hf == p.ActiveIn() {
+		setIntWithKey(p.ID, ic.DAO, feePerByteKey, defaultFeePerByte)
+		setIntWithKey(p.ID, ic.DAO, execFeeFactorKey, defaultExecFeeFactor)
+		setIntWithKey(p.ID, ic.DAO, storagePriceKey, DefaultStoragePrice)
+
+		cache := &PolicyCache{
+			execFeeFactor:      defaultExecFeeFactor,
+			feePerByte:         defaultFeePerByte,
+			maxVerificationGas: defaultMaxVerificationGas,
+			storagePrice:       DefaultStoragePrice,
+			attributeFee:       map[transaction.AttrType]uint32{},
+			blockedAccounts:    make([]util.Uint160, 0),
+		}
+		ic.DAO.SetCache(p.ID, cache)
 	}
-	if p.p2pSigExtensionsEnabled {
+	if hf != nil && *hf == transaction.NotaryAssistedActivation {
 		setIntWithKey(p.ID, ic.DAO, []byte{attributeFeePrefix, byte(transaction.NotaryAssistedT)}, defaultNotaryAssistedFee)
+
+		cache := ic.DAO.GetRWCache(p.ID).(*PolicyCache)
 		cache.attributeFee[transaction.NotaryAssistedT] = defaultNotaryAssistedFee
 	}
-	ic.DAO.SetCache(p.ID, cache)
 
 	return nil
 }
@@ -363,9 +368,18 @@ func (p *Policy) setStoragePrice(ic *interop.Context, args []stackitem.Item) sta
 	return stackitem.Null{}
 }
 
-func (p *Policy) getAttributeFee(ic *interop.Context, args []stackitem.Item) stackitem.Item {
+func (p *Policy) getAttributeFeeV0(ic *interop.Context, args []stackitem.Item) stackitem.Item {
+	return p.getAttributeFeeGeneric(ic, args, false)
+}
+
+func (p *Policy) getAttributeFeeV1(ic *interop.Context, args []stackitem.Item) stackitem.Item {
+	return p.getAttributeFeeGeneric(ic, args, true)
+}
+
+func (p *Policy) getAttributeFeeGeneric(ic *interop.Context, args []stackitem.Item, allowNotaryAssisted bool) stackitem.Item {
 	t := transaction.AttrType(toUint8(args[0]))
-	if !transaction.IsValidAttrType(ic.Chain.GetConfig().ReservedAttributes, t) {
+	if !transaction.IsValidAttrType(ic.Chain.GetConfig().ReservedAttributes, t) ||
+		(!allowNotaryAssisted && t == transaction.NotaryAssistedT) {
 		panic(fmt.Errorf("invalid attribute type: %d", t))
 	}
 	return stackitem.NewBigInteger(big.NewInt(p.GetAttributeFeeInternal(ic.DAO, t)))
@@ -382,10 +396,19 @@ func (p *Policy) GetAttributeFeeInternal(d *dao.Simple, t transaction.AttrType)
 	return int64(v)
 }
 
-func (p *Policy) setAttributeFee(ic *interop.Context, args []stackitem.Item) stackitem.Item {
+func (p *Policy) setAttributeFeeV0(ic *interop.Context, args []stackitem.Item) stackitem.Item {
+	return p.setAttributeFeeGeneric(ic, args, false)
+}
+
+func (p *Policy) setAttributeFeeV1(ic *interop.Context, args []stackitem.Item) stackitem.Item {
+	return p.setAttributeFeeGeneric(ic, args, true)
+}
+
+func (p *Policy) setAttributeFeeGeneric(ic *interop.Context, args []stackitem.Item, allowNotaryAssisted bool) stackitem.Item {
 	t := transaction.AttrType(toUint8(args[0]))
 	value := toUint32(args[1])
-	if !transaction.IsValidAttrType(ic.Chain.GetConfig().ReservedAttributes, t) {
+	if !transaction.IsValidAttrType(ic.Chain.GetConfig().ReservedAttributes, t) ||
+		(!allowNotaryAssisted && t == transaction.NotaryAssistedT) {
 		panic(fmt.Errorf("invalid attribute type: %d", t))
 	}
 	if value > maxAttributeFee {
diff --git a/pkg/core/native/policy_test.go b/pkg/core/native/policy_test.go
index 9569dd6b83..a1d95fe568 100644
--- a/pkg/core/native/policy_test.go
+++ b/pkg/core/native/policy_test.go
@@ -4,9 +4,12 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/nspcc-dev/neo-go/pkg/config"
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/native"
+	"github.com/nspcc-dev/neo-go/pkg/core/native/nativehashes"
 	"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
+	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/neotest"
 	"github.com/nspcc-dev/neo-go/pkg/neotest/chain"
 	"github.com/stretchr/testify/require"
@@ -65,3 +68,51 @@ func TestPolicy_BlockedAccounts(t *testing.T) {
 		require.Equal(t, expectedErr, err.Error())
 	})
 }
+
+func TestPolicy_GetNotaryFeePerKey(t *testing.T) {
+	const echidnaHeight = 4
+	bc, acc := chain.NewSingleWithCustomConfig(t, func(c *config.Blockchain) {
+		c.Hardforks = map[string]uint32{
+			config.HFEchidna.String(): echidnaHeight,
+		}
+	})
+	e := neotest.NewExecutor(t, bc, acc, acc)
+	p := e.CommitteeInvoker(nativehashes.PolicyContract)
+
+	// Invoke before Echidna should fail.
+	p.InvokeFail(t, "invalid attribute type: 34", "getAttributeFee", int64(transaction.NotaryAssistedT))
+
+	for e.Chain.BlockHeight() < echidnaHeight-1 {
+		e.AddNewBlock(t)
+	}
+
+	// Invoke at Echidna should return the default value.
+	p.Invoke(t, 1000_0000, "getAttributeFee", int64(transaction.NotaryAssistedT))
+
+	// Invoke after Echidna should return the default value.
+	p.Invoke(t, 1000_0000, "getAttributeFee", int64(transaction.NotaryAssistedT))
+}
+
+func TestPolicy_SetNotaryFeePerKey(t *testing.T) {
+	const echidnaHeight = 4
+	bc, acc := chain.NewSingleWithCustomConfig(t, func(c *config.Blockchain) {
+		c.Hardforks = map[string]uint32{
+			config.HFEchidna.String(): echidnaHeight,
+		}
+	})
+	e := neotest.NewExecutor(t, bc, acc, acc)
+	p := e.CommitteeInvoker(nativehashes.PolicyContract)
+
+	// Invoke before Echidna should fail.
+	p.InvokeFail(t, "invalid attribute type: 34", "setAttributeFee", int64(transaction.NotaryAssistedT), 500_0000)
+
+	for e.Chain.BlockHeight() < echidnaHeight-1 {
+		e.AddNewBlock(t)
+	}
+
+	// Invoke at Echidna should return the default value.
+	p.Invoke(t, nil, "setAttributeFee", int64(transaction.NotaryAssistedT), 500_0000)
+
+	// Invoke after Echidna should return the default value.
+	p.Invoke(t, nil, "setAttributeFee", int64(transaction.NotaryAssistedT), 510_0000)
+}
diff --git a/pkg/core/transaction/notary_assisted.go b/pkg/core/transaction/notary_assisted.go
index 278aaea936..8f857bfd04 100644
--- a/pkg/core/transaction/notary_assisted.go
+++ b/pkg/core/transaction/notary_assisted.go
@@ -1,9 +1,14 @@
 package transaction
 
 import (
+	"github.com/nspcc-dev/neo-go/pkg/config"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 )
 
+// NotaryAssistedActivation stores the hardfork of NotaryAssisted transaction attribute
+// activation.
+var NotaryAssistedActivation = config.HFEchidna
+
 // NotaryAssisted represents attribute for notary service transactions.
 type NotaryAssisted struct {
 	NKeys uint8 `json:"nkeys"`