A man contracted marriage with his wife using a name other than her name in the contract; what is the ruling in this case, and if the assumed name matches the name of her sister, what is the ruling, and is the contract valid?

The questioner : I have been married to my cousin’s daughter for five or six years, but at the time of the marriage contract, I contracted with her using a name other than her name. What is the ruling in this case? And if the assumed name matches the name of her sister, what is the ruling in that case as well? Is my marriage contract with her valid?

The Shaykh : First, I advise you and others to avoid such disgraceful actions that are not befitting a believer to lie and to present matters in a form that is not the truth, due to the great danger involved, especially in matters such as marriage.
As for this contract, if the wife is specifically identified to you, to the guardian, and to the witnesses, but the lie was only in the name, then the marriage is valid, because what matters is the meaning, not the wording.
However, if the situation is different, then the contract must be examined. Accordingly, if it is known to you, to her guardian, and to the witnesses that the one you contracted with is a specific, identified woman, but she was called by a name other than her own, then the marriage is valid. You must repent to Allah and correct the name to match the reality.