diff --git a/cli/nep17_test.go b/cli/nep17_test.go
index 1f7b9c824..e74b1563e 100644
--- a/cli/nep17_test.go
+++ b/cli/nep17_test.go
@@ -158,6 +158,22 @@ func TestNEP17Transfer(t *testing.T) {
 		b, _ = e.Chain.GetGoverningTokenBalance(sh)
 		require.Equal(t, big.NewInt(41), b)
 	})
+
+	t.Run("with data", func(t *testing.T) {
+		e.In.WriteString("one\r")
+		validTil := e.Chain.BlockHeight() + 100
+		e.Run(t, []string{
+			"neo-go", "wallet", "nep17", "transfer",
+			"--rpc-endpoint", "http://" + e.RPC.Addr,
+			"--wallet", validatorWallet,
+			"--to", address.Uint160ToString(e.Chain.GetNotaryContractScriptHash()),
+			"--token", "GAS",
+			"--amount", "1",
+			"--from", validatorAddr,
+			"[", validatorAddr, strconv.Itoa(int(validTil)), "]",
+		}...)
+		e.checkTxPersisted(t)
+	})
 }
 
 func TestNEP17MultiTransfer(t *testing.T) {
diff --git a/cli/smartcontract/smart_contract.go b/cli/smartcontract/smart_contract.go
index 9436c4ad6..d7f7224fb 100644
--- a/cli/smartcontract/smart_contract.go
+++ b/cli/smartcontract/smart_contract.go
@@ -538,7 +538,7 @@ func invokeInternal(ctx *cli.Context, signAndPush bool) error {
 	paramsStart++
 
 	if len(args) > paramsStart {
-		cosignersOffset, params, err = parseParams(args[paramsStart:], true)
+		cosignersOffset, params, err = ParseParams(args[paramsStart:], true)
 		if err != nil {
 			return cli.NewExitError(err, 1)
 		}
@@ -623,12 +623,12 @@ func invokeInternal(ctx *cli.Context, signAndPush bool) error {
 	return nil
 }
 
-// parseParams extracts array of smartcontract.Parameter from the given args and
+// ParseParams extracts array of smartcontract.Parameter from the given args and
 // returns the number of handled words, the array itself and an error.
 // `calledFromMain` denotes whether the method was called from the outside or
 // recursively and used to check if cosignersSeparator and closing bracket are
 // allowed to be in `args` sequence.
-func parseParams(args []string, calledFromMain bool) (int, []smartcontract.Parameter, error) {
+func ParseParams(args []string, calledFromMain bool) (int, []smartcontract.Parameter, error) {
 	res := []smartcontract.Parameter{}
 	for k := 0; k < len(args); {
 		s := args[k]
@@ -639,7 +639,7 @@ func parseParams(args []string, calledFromMain bool) (int, []smartcontract.Param
 			}
 			return 0, []smartcontract.Parameter{}, errors.New("invalid array syntax: missing closing bracket")
 		case arrayStartSeparator:
-			numWordsRead, array, err := parseParams(args[k+1:], false)
+			numWordsRead, array, err := ParseParams(args[k+1:], false)
 			if err != nil {
 				return 0, nil, fmt.Errorf("failed to parse array: %w", err)
 			}
@@ -887,6 +887,26 @@ func contractDeploy(ctx *cli.Context) error {
 	return nil
 }
 
+// GetDataFromContext returns data parameter from context args.
+func GetDataFromContext(ctx *cli.Context) (interface{}, *cli.ExitError) {
+	var data interface{}
+	args := ctx.Args()
+	if args.Present() {
+		_, params, err := ParseParams(args, true)
+		if err != nil {
+			return nil, cli.NewExitError(fmt.Errorf("unable to parse 'data' parameter: %w", err), 1)
+		}
+		if len(params) != 1 {
+			return nil, cli.NewExitError("'data' should be represented as a single parameter", 1)
+		}
+		data, err = smartcontract.ExpandParameterToEmitable(params[0])
+		if err != nil {
+			return nil, cli.NewExitError(fmt.Sprintf("failed to convert 'data' to emitable type: %s", err.Error()), 1)
+		}
+	}
+	return data, nil
+}
+
 // ParseContractConfig reads contract configuration file (.yaml) and returns unmarshalled ProjectConfig.
 func ParseContractConfig(confFile string) (ProjectConfig, error) {
 	conf := ProjectConfig{}
diff --git a/cli/smartcontract/smart_contract_test.go b/cli/smartcontract/smart_contract_test.go
index 64e8811fb..89af4f7be 100644
--- a/cli/smartcontract/smart_contract_test.go
+++ b/cli/smartcontract/smart_contract_test.go
@@ -202,7 +202,7 @@ func TestParseParams_CalledFromItself(t *testing.T) {
 
 	for str, expected := range testCases {
 		input := strings.Split(str, " ")
-		offset, actual, err := parseParams(input, false)
+		offset, actual, err := ParseParams(input, false)
 		require.NoError(t, err)
 		require.Equal(t, expected.WordsRead, offset)
 		require.Equal(t, expected.Value, actual)
@@ -218,7 +218,7 @@ func TestParseParams_CalledFromItself(t *testing.T) {
 
 	for _, str := range errorCases {
 		input := strings.Split(str, " ")
-		_, _, err := parseParams(input, false)
+		_, _, err := ParseParams(input, false)
 		require.Error(t, err)
 	}
 }
@@ -400,7 +400,7 @@ func TestParseParams_CalledFromOutside(t *testing.T) {
 	}
 	for str, expected := range testCases {
 		input := strings.Split(str, " ")
-		offset, arr, err := parseParams(input, true)
+		offset, arr, err := ParseParams(input, true)
 		require.NoError(t, err)
 		require.Equal(t, expected.WordsRead, offset)
 		require.Equal(t, expected.Parameters, arr)
@@ -415,7 +415,7 @@ func TestParseParams_CalledFromOutside(t *testing.T) {
 	}
 	for _, str := range errorCases {
 		input := strings.Split(str, " ")
-		_, _, err := parseParams(input, true)
+		_, _, err := ParseParams(input, true)
 		require.Error(t, err)
 	}
 }
diff --git a/cli/wallet/nep17.go b/cli/wallet/nep17.go
index a2185946a..70817a15b 100644
--- a/cli/wallet/nep17.go
+++ b/cli/wallet/nep17.go
@@ -9,6 +9,7 @@ import (
 	"github.com/nspcc-dev/neo-go/cli/flags"
 	"github.com/nspcc-dev/neo-go/cli/options"
 	"github.com/nspcc-dev/neo-go/cli/paramcontext"
+	smartcontractcli "github.com/nspcc-dev/neo-go/cli/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/fixedn"
 	"github.com/nspcc-dev/neo-go/pkg/rpc/client"
@@ -111,9 +112,12 @@ func newNEP17Commands() []cli.Command {
 		{
 			Name:      "transfer",
 			Usage:     "transfer NEP17 tokens",
-			UsageText: "transfer --wallet <path> --rpc-endpoint <node> --timeout <time> --from <addr> --to <addr> --token <hash> --amount string",
+			UsageText: "transfer --wallet <path> --rpc-endpoint <node> --timeout <time> --from <addr> --to <addr> --token <hash> --amount string [data]",
 			Action:    transferNEP17,
 			Flags:     transferFlags,
+			Description: `Transfers specified NEP17 token amount with optional 'data' parameter attached to the transfer.
+   See 'contract testinvokefunction' documentation for the details about 'data'
+   parameter. If no 'data' is given then default nil value will be used`,
 		},
 		{
 			Name:  "multitransfer",
@@ -409,6 +413,7 @@ func multiTransferNEP17(ctx *cli.Context) error {
 			Token:   token.Hash,
 			Address: addr,
 			Amount:  amount.Int64(),
+			Data:    nil,
 		})
 	}
 
@@ -456,17 +461,23 @@ func transferNEP17(ctx *cli.Context) error {
 		return cli.NewExitError(fmt.Errorf("invalid amount: %w", err), 1)
 	}
 
+	data, extErr := smartcontractcli.GetDataFromContext(ctx)
+	if extErr != nil {
+		return extErr
+	}
+
 	return signAndSendTransfer(ctx, c, acc, []client.TransferTarget{{
 		Token:   token.Hash,
 		Address: to,
 		Amount:  amount.Int64(),
+		Data:    data,
 	}})
 }
 
 func signAndSendTransfer(ctx *cli.Context, c *client.Client, acc *wallet.Account, recipients []client.TransferTarget) error {
 	gas := flags.Fixed8FromContext(ctx, "gas")
 
-	tx, err := c.CreateNEP17MultiTransferTx(acc, int64(gas), recipients, nil)
+	tx, err := c.CreateNEP17MultiTransferTx(acc, int64(gas), recipients)
 	if err != nil {
 		return cli.NewExitError(err, 1)
 	}
diff --git a/config/protocol.unit_testnet.single.yml b/config/protocol.unit_testnet.single.yml
index dc47603ad..076487504 100644
--- a/config/protocol.unit_testnet.single.yml
+++ b/config/protocol.unit_testnet.single.yml
@@ -8,7 +8,7 @@ ProtocolConfiguration:
   ValidatorsCount: 1
   VerifyBlocks: true
   VerifyTransactions: true
-  P2PSigExtensions: false
+  P2PSigExtensions: true
   NativeActivations:
     ContractManagement: [0]
     StdLib: [0]
@@ -20,6 +20,7 @@ ProtocolConfiguration:
     RoleManagement: [0]
     OracleContract: [0]
     NameService: [0]
+    Notary: [0]
 
 ApplicationConfiguration:
   # LogPath could be set up in case you need stdout logs to some proper file.
diff --git a/pkg/rpc/client/nep17.go b/pkg/rpc/client/nep17.go
index 51d7b5ed7..3b27ebf54 100644
--- a/pkg/rpc/client/nep17.go
+++ b/pkg/rpc/client/nep17.go
@@ -13,11 +13,12 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/wallet"
 )
 
-// TransferTarget represents target address and token amount for transfer.
+// TransferTarget represents target address, token amount and data for transfer.
 type TransferTarget struct {
 	Token   util.Uint160
 	Address util.Uint160
 	Amount  int64
+	Data    interface{}
 }
 
 // SignerAccount represents combination of the transaction.Signer and the
@@ -73,28 +74,22 @@ func (c *Client) CreateNEP17TransferTx(acc *wallet.Account, to util.Uint160, tok
 		{Token: token,
 			Address: to,
 			Amount:  amount,
+			Data:    data,
 		},
-	}, []interface{}{data})
+	})
 }
 
 // CreateNEP17MultiTransferTx creates an invocation transaction for performing NEP17 transfers
 // from a single sender to multiple recipients with the given data.
-func (c *Client) CreateNEP17MultiTransferTx(acc *wallet.Account, gas int64, recipients []TransferTarget, data []interface{}) (*transaction.Transaction, error) {
+func (c *Client) CreateNEP17MultiTransferTx(acc *wallet.Account, gas int64, recipients []TransferTarget) (*transaction.Transaction, error) {
 	from, err := address.StringToUint160(acc.Address)
 	if err != nil {
 		return nil, fmt.Errorf("bad account address: %w", err)
 	}
-	if data == nil {
-		data = make([]interface{}, len(recipients))
-	} else {
-		if len(data) != len(recipients) {
-			return nil, fmt.Errorf("data and recipients number mismatch: %d vs %d", len(data), len(recipients))
-		}
-	}
 	w := io.NewBufBinWriter()
 	for i := range recipients {
 		emit.AppCall(w.BinWriter, recipients[i].Token, "transfer", callflag.All,
-			from, recipients[i].Address, recipients[i].Amount, data[i])
+			from, recipients[i].Address, recipients[i].Amount, recipients[i].Data)
 		emit.Opcodes(w.BinWriter, opcode.ASSERT)
 	}
 	if w.Err != nil {
@@ -167,12 +162,12 @@ func (c *Client) TransferNEP17(acc *wallet.Account, to util.Uint160, token util.
 }
 
 // MultiTransferNEP17 is similar to TransferNEP17, buf allows to have multiple recipients.
-func (c *Client) MultiTransferNEP17(acc *wallet.Account, gas int64, recipients []TransferTarget, data []interface{}) (util.Uint256, error) {
+func (c *Client) MultiTransferNEP17(acc *wallet.Account, gas int64, recipients []TransferTarget) (util.Uint256, error) {
 	if !c.initDone {
 		return util.Uint256{}, errNetworkNotInitialized
 	}
 
-	tx, err := c.CreateNEP17MultiTransferTx(acc, gas, recipients, data)
+	tx, err := c.CreateNEP17MultiTransferTx(acc, gas, recipients)
 	if err != nil {
 		return util.Uint256{}, err
 	}
diff --git a/pkg/smartcontract/parameter.go b/pkg/smartcontract/parameter.go
index 5c870add7..d961b191e 100644
--- a/pkg/smartcontract/parameter.go
+++ b/pkg/smartcontract/parameter.go
@@ -14,6 +14,7 @@ import (
 	"strings"
 	"unicode/utf8"
 
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 )
@@ -437,3 +438,28 @@ func NewParameterFromString(in string) (*Parameter, error) {
 	}
 	return res, nil
 }
+
+// ExpandParameterToEmitable converts parameter to a type which can be handled as
+// an array item by emit.Array. It correlates with the way RPC server handles
+// FuncParams for invoke* calls inside the request.ExpandArrayIntoScript function.
+func ExpandParameterToEmitable(param Parameter) (interface{}, error) {
+	var err error
+	switch t := param.Type; t {
+	case PublicKeyType:
+		return param.Value.(*keys.PublicKey).Bytes(), nil
+	case ArrayType:
+		arr := param.Value.([]Parameter)
+		res := make([]interface{}, len(arr))
+		for i := range arr {
+			res[i], err = ExpandParameterToEmitable(arr[i])
+			if err != nil {
+				return nil, err
+			}
+		}
+		return res, nil
+	case MapType, InteropInterfaceType, UnknownType, AnyType, VoidType:
+		return nil, fmt.Errorf("unsupported parameter type: %s", t.String())
+	default:
+		return param.Value, nil
+	}
+}
diff --git a/pkg/smartcontract/parameter_test.go b/pkg/smartcontract/parameter_test.go
index 45b421568..021f9ca9d 100644
--- a/pkg/smartcontract/parameter_test.go
+++ b/pkg/smartcontract/parameter_test.go
@@ -9,7 +9,10 @@ import (
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/testserdes"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/vm/emit"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -517,3 +520,85 @@ func hexToBase64(s string) string {
 	b, _ := hex.DecodeString(s)
 	return base64.StdEncoding.EncodeToString(b)
 }
+
+func TestExpandParameterToEmitable(t *testing.T) {
+	pk, _ := keys.NewPrivateKey()
+	testCases := []struct {
+		In       Parameter
+		Expected interface{}
+	}{
+		{
+			In:       Parameter{Type: BoolType, Value: true},
+			Expected: true,
+		},
+		{
+			In:       Parameter{Type: IntegerType, Value: int64(123)},
+			Expected: int64(123),
+		},
+		{
+			In:       Parameter{Type: ByteArrayType, Value: []byte{1, 2, 3}},
+			Expected: []byte{1, 2, 3},
+		},
+		{
+			In:       Parameter{Type: StringType, Value: "writing's on the wall"},
+			Expected: "writing's on the wall",
+		},
+		{
+			In:       Parameter{Type: Hash160Type, Value: util.Uint160{1, 2, 3}},
+			Expected: util.Uint160{1, 2, 3},
+		},
+		{
+			In:       Parameter{Type: Hash256Type, Value: util.Uint256{1, 2, 3}},
+			Expected: util.Uint256{1, 2, 3},
+		},
+		{
+			In:       Parameter{Type: PublicKeyType, Value: pk.PublicKey()},
+			Expected: pk.PublicKey().Bytes(),
+		},
+		{
+			In:       Parameter{Type: SignatureType, Value: []byte{1, 2, 3}},
+			Expected: []byte{1, 2, 3},
+		},
+		{
+			In: Parameter{Type: ArrayType, Value: []Parameter{
+				{
+					Type:  IntegerType,
+					Value: int64(123),
+				},
+				{
+					Type:  ByteArrayType,
+					Value: []byte{1, 2, 3},
+				},
+				{
+					Type: ArrayType,
+					Value: []Parameter{
+						{
+							Type:  BoolType,
+							Value: true,
+						},
+					},
+				},
+			}},
+			Expected: []interface{}{int64(123), []byte{1, 2, 3}, []interface{}{true}},
+		},
+	}
+	bw := io.NewBufBinWriter()
+	for _, testCase := range testCases {
+		actual, err := ExpandParameterToEmitable(testCase.In)
+		require.NoError(t, err)
+		require.Equal(t, testCase.Expected, actual)
+
+		emit.Array(bw.BinWriter, actual)
+		require.NoError(t, bw.Err)
+	}
+	errCases := []Parameter{
+		{Type: AnyType},
+		{Type: UnknownType},
+		{Type: MapType},
+		{Type: InteropInterfaceType},
+	}
+	for _, errCase := range errCases {
+		_, err := ExpandParameterToEmitable(errCase)
+		require.Error(t, err)
+	}
+}
diff --git a/pkg/vm/emit/emit.go b/pkg/vm/emit/emit.go
index 55949f8cb..9c6da396a 100644
--- a/pkg/vm/emit/emit.go
+++ b/pkg/vm/emit/emit.go
@@ -88,6 +88,8 @@ func Array(w *io.BinWriter, es ...interface{}) {
 			String(w, e)
 		case util.Uint160:
 			Bytes(w, e.BytesBE())
+		case util.Uint256:
+			Bytes(w, e.BytesBE())
 		case []byte:
 			Bytes(w, e)
 		case bool: