The Muslim Institute is launching a new standard marriage contract for British Muslims marrying under Sharia law.
The new contract, called a nikah, will provide a wife with written proof of the marriage and of the terms and conditions agreed between the spouses.
This is set to have particular ramifications for cases of divorce where Muslim women have found it difficult to secure financial support.
Previously, couples could also have a civil ceremony, in addition to a nikah, to gain protection under British law.
With this latest change, family lawyers say, the Sharia service itself will guarantee financial rights.