Nikah On Phone
Under Quran, presence of witnesses is not mandatory for the solemnization of marriage, unlike divorce where witnesses are mandatory (65:2). Therefore, marriage contracted without witnesses is valid. Similarly, presence of a cleric is also not a mandatory requirement for marriage. However, please note that Quran discourages the concept of taking secret love-companions (4:25), so the spirit of Quran stipulates that marriage should not be kept secret.
As per Ghamidi sb understanding, this nikah is not valid please see Discussion 45473