1 files changed, 1 insertions, 0 deletions
diff --git a/errors.go b/errors.go
index fd57ccc..21973fa 100644
--- a/errors.go
+++ b/errors.go
@@ -5,4 +5,5 @@ import "errors"
 var (
 	ErrInvalidNumber   = errors.New("invalid number")   // number contains non numeric symbols
 	ErrInvalidChecksum = errors.New("invalid checksum") // number not correct by luhn algorithm
+	ErrNotImplemented  = errors.New("not implemented")  // not implemented currently
 )