diff --git a/globalplatform/command_set.go b/globalplatform/command_set.go
index 05ff649..8072670 100644
--- a/globalplatform/command_set.go
+++ b/globalplatform/command_set.go
@@ -7,22 +7,13 @@ import (
 	"os"
 
 	"github.com/status-im/keycard-go/apdu"
-)
-
-var (
-	CardManagerAID = []byte{0xa0, 0x00, 0x00, 0x01, 0x51, 0x00, 0x00, 0x00}
-	CardTestKey    = []byte{0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f}
-	AppletPkgAID   = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01}
-
-	WalletAID         = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01, 0x01}
-	WalletInstanceAID = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01, 0x01, 0x01}
-
-	NdefAppletAID   = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01, 0x02}
-	NdefInstanceAID = []byte{0xD2, 0x76, 0x00, 0x00, 0x85, 0x01, 0x01}
+	"github.com/status-im/keycard-go/identifiers"
 )
 
 type LoadingCallback = func(loadingBlock, totalBlocks int)
 
+const defaultKeycardInstanceAID = 1
+
 type CommandSet struct {
 	c       Channel
 	session *Session
@@ -40,7 +31,7 @@ func (cs *CommandSet) Select() error {
 		InsSelect,
 		uint8(0x04),
 		uint8(0x00),
-		CardManagerAID,
+		identifiers.CardManagerAID,
 	)
 
 	resp, err := cs.c.Send(cmd)
@@ -62,10 +53,15 @@ func (cs *CommandSet) OpenSecureChannel() error {
 }
 
 func (cs *CommandSet) DeleteKeycardInstancesAndPackage() error {
+	instanceAID, err := identifiers.KeycardInstanceAID(defaultKeycardInstanceAID)
+	if err != nil {
+		return err
+	}
+
 	ids := [][]byte{
-		NdefInstanceAID,
-		WalletInstanceAID,
-		AppletPkgAID,
+		identifiers.NdefInstanceAID,
+		instanceAID,
+		identifiers.PackageAID,
 	}
 
 	for _, id := range ids {
@@ -80,7 +76,7 @@ func (cs *CommandSet) DeleteKeycardInstancesAndPackage() error {
 }
 
 func (cs *CommandSet) LoadKeycardPackage(capFile *os.File, callback LoadingCallback) error {
-	preLoad := NewCommandInstallForLoad(AppletPkgAID, CardManagerAID)
+	preLoad := NewCommandInstallForLoad(identifiers.PackageAID, identifiers.CardManagerAID)
 	resp, err := cs.c.Send(preLoad)
 	if err = cs.checkOK(resp, err); err != nil {
 		return err
@@ -104,11 +100,24 @@ func (cs *CommandSet) LoadKeycardPackage(capFile *os.File, callback LoadingCallb
 }
 
 func (cs *CommandSet) InstallNDEFApplet(ndefRecord []byte) error {
-	return cs.installForInstall(AppletPkgAID, NdefAppletAID, NdefInstanceAID, ndefRecord)
+	return cs.installForInstall(
+		identifiers.PackageAID,
+		identifiers.NdefAID,
+		identifiers.NdefInstanceAID,
+		ndefRecord)
 }
 
 func (cs *CommandSet) InstallKeycardApplet() error {
-	return cs.installForInstall(AppletPkgAID, WalletAID, WalletInstanceAID, []byte{})
+	instanceAID, err := identifiers.KeycardInstanceAID(defaultKeycardInstanceAID)
+	if err != nil {
+		return err
+	}
+
+	return cs.installForInstall(
+		identifiers.PackageAID,
+		identifiers.KeycardAID,
+		instanceAID,
+		[]byte{})
 }
 
 func (cs *CommandSet) installForInstall(packageAID, appletAID, instanceAID, params []byte) error {
@@ -125,7 +134,7 @@ func (cs *CommandSet) initializeUpdate(hostChallenge []byte) error {
 	}
 
 	// verify cryptogram and initialize session keys
-	keys := NewSCP02Keys(CardTestKey, CardTestKey)
+	keys := NewSCP02Keys(identifiers.CardTestKey, identifiers.CardTestKey)
 	session, err := NewSession(keys, resp, hostChallenge)
 	cs.c = NewSecureChannel(session, cs.c)
 	cs.session = session
diff --git a/identifiers/identifiers.go b/identifiers/identifiers.go
new file mode 100644
index 0000000..437987b
--- /dev/null
+++ b/identifiers/identifiers.go
@@ -0,0 +1,23 @@
+package identifiers
+
+import "errors"
+
+var (
+	CardManagerAID = []byte{0xa0, 0x00, 0x00, 0x01, 0x51, 0x00, 0x00, 0x00}
+	CardTestKey    = []byte{0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f}
+
+	PackageAID      = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01}
+	KeycardAID      = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01, 0x01}
+	NdefAID         = []byte{0xA0, 0x00, 0x00, 0x08, 0x04, 0x00, 0x01, 0x02}
+	NdefInstanceAID = []byte{0xD2, 0x76, 0x00, 0x00, 0x85, 0x01, 0x01}
+
+	ErrInvalidInstanceIndex = errors.New("instance index must be between 1 and 255")
+)
+
+func KeycardInstanceAID(index int) ([]byte, error) {
+	if index < 0x01 || index > 0xFF {
+		return nil, ErrInvalidInstanceIndex
+	}
+
+	return append(KeycardAID, byte(index)), nil
+}