public static string IsValidPhone(string phone) { if (string.IsNullOrWhiteSpace(phone)) { return(null); } if (phone[0] != '+') { return(null); } try { PhoneNumber number = PhoneNumberUtil.GetInstance().Parse(phone, "US"); return(PhoneNumberUtil.GetInstance().Format(number, PhoneNumberFormat.INTERNATIONAL)); } catch (Exception ex) { Insight.Track("IsValidPhone try-catch"); Insight.Track(ex.ToString()); return(null); } }