Praise be to Allaah.
Ibn Qudaamah (may Allaah have mercy on him) said:
“Chapter Three: if the husband and wife become Muslim together,
then they keep their original marriage contract, whether this happens before the marriage
is consummated or after. There is no dispute among the scholars on this matter, praise be
Ibn ‘Abd al-Barr mentioned that there is scholarly consensus on
the matter. The reason is that there is no difference of religion between the spouses. Abu
Dawood reported from Ibn ‘Abbaas that a man came to declare his Islam at the time of
the Messenger of Allaah
(peace and blessings of Allaah be upon him), then his wife came
to declare her Islam. [The man] said: ‘O Messenger of Allaah, she became Muslim when
I did.’ So the Prophet
(peace and blessings of Allaah be upon him) returned her to
(al-Mughni, part 7, Ahkaam al-Nikaah).
On the basis of the above, their original marriage contract is
sufficient, and there is no need for them to do a new one. And Allaah knows best.