diff --git a/common/transfer_statements.go b/common/transfer_statements.go
index adbdeaf..dd8324a 100644
--- a/common/transfer_statements.go
+++ b/common/transfer_statements.go
@@ -63,7 +63,7 @@ func GetTransferData(ctx context.Context, db storage.PrefixDb, publicKey string,
 	for _, key := range keys {
 		value, err := db.Get(ctx, key.ToBytes())
 		if err != nil {
-			return "", fmt.Errorf("failed to get %s: %v", key, err)
+			return "", fmt.Errorf("failed to get %s: %v", key.ToBytes(), err)
 		}
 		data[key] = string(value)
 	}
diff --git a/common/vouchers_test.go b/common/vouchers_test.go
index 9f5bf85..9ba7cbc 100644
--- a/common/vouchers_test.go
+++ b/common/vouchers_test.go
@@ -86,16 +86,16 @@ func TestGetVoucherData(t *testing.T) {
 	spdb := storage.NewSubPrefixDb(db, []byte("vouchers"))
 
 	// Test voucher data
-	mockData := map[string][]byte{
-		"sym":  []byte("1:SRF\n2:MILO"),
-		"bal":  []byte("1:100\n2:200"),
-		"deci": []byte("1:6\n2:4"),
-		"addr": []byte("1:0xd4c288865Ce\n2:0x41c188d63Qa"),
+	mockData := map[DataTyp][]byte{
+		DATA_PREFIX_SYMBOLS:   []byte("1:SRF\n2:MILO"),
+		DATA_PREFIX_BALANCES:  []byte("1:100\n2:200"),
+		DATA_PREFIX_DECIMALS:  []byte("1:6\n2:4"),
+		DATA_PREFIX_ADDRESSES: []byte("1:0xd4c288865Ce\n2:0x41c188d63Qa"),
 	}
 
 	// Put the data
 	for key, value := range mockData {
-		err = spdb.Put(ctx, []byte(key), []byte(value))
+		err = spdb.Put(ctx, []byte(key.ToBytes()), []byte(value))
 		if err != nil {
 			t.Fatal(err)
 		}
diff --git a/internal/handlers/ussd/menuhandler_test.go b/internal/handlers/ussd/menuhandler_test.go
index d7cd855..4e53228 100644
--- a/internal/handlers/ussd/menuhandler_test.go
+++ b/internal/handlers/ussd/menuhandler_test.go
@@ -1937,7 +1937,7 @@ func TestCheckVouchers(t *testing.T) {
 	assert.NoError(t, err)
 
 	// Read voucher sym data from the store
-	voucherData, err := spdb.Get(ctx, []byte("sym"))
+	voucherData, err := spdb.Get(ctx, common.DATA_PREFIX_SYMBOLS.ToBytes())
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1961,7 +1961,7 @@ func TestGetVoucherList(t *testing.T) {
 	expectedSym := []byte("1:SRF\n2:MILO")
 
 	// Put voucher sym data from the store
-	err := spdb.Put(ctx, []byte("sym"), expectedSym)
+	err := spdb.Put(ctx, common.DATA_PREFIX_SYMBOLS.ToBytes(), expectedSym)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1991,16 +1991,16 @@ func TestViewVoucher(t *testing.T) {
 	}
 
 	// Define mock voucher data
-	mockData := map[string][]byte{
-		"sym":  []byte("1:SRF\n2:MILO"),
-		"bal":  []byte("1:100\n2:200"),
-		"deci": []byte("1:6\n2:4"),
-		"addr": []byte("1:0xd4c288865Ce\n2:0x41c188d63Qa"),
+	mockData := map[common.DataTyp][]byte{
+		common.DATA_PREFIX_SYMBOLS:   []byte("1:SRF\n2:MILO"),
+		common.DATA_PREFIX_BALANCES:  []byte("1:100\n2:200"),
+		common.DATA_PREFIX_DECIMALS:  []byte("1:6\n2:4"),
+		common.DATA_PREFIX_ADDRESSES: []byte("1:0xd4c288865Ce\n2:0x41c188d63Qa"),
 	}
 
 	// Put the data
 	for key, value := range mockData {
-		err = spdb.Put(ctx, []byte(key), []byte(value))
+		err = spdb.Put(ctx, []byte(key.ToBytes()), []byte(value))
 		if err != nil {
 			t.Fatal(err)
 		}