diff --git a/cmd/callsign_test.go b/cmd/callsign_test.go
new file mode 100644
index 0000000..ab2a1df
--- /dev/null
+++ b/cmd/callsign_test.go
@@ -0,0 +1,30 @@
+package cmd
+
+import "testing"
+
+func TestValidateCall(t *testing.T) {
+	type args struct {
+		sign string
+	}
+	tests := []struct {
+		name         string
+		args 		 args
+		//args         string
+		wantCall     string
+		wantErrorMsg string
+	}{
+		{"Good call (simple)", args.String("on4kjm"), "ON4KJM", ""},
+		{"Good call (suffix)", "on4kjm/p", "ON4KJM/P", ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotCall, gotErrorMsg := ValidateCall(tt.args.sign)
+			if gotCall != tt.wantCall {
+				t.Errorf("ValidateCall() gotCall = %v, want %v", gotCall, tt.wantCall)
+			}
+			if gotErrorMsg != tt.wantErrorMsg {
+				t.Errorf("ValidateCall() gotErrorMsg = %v, want %v", gotErrorMsg, tt.wantErrorMsg)
+			}
+		})
+	}
+}