The general rule is that monies inherited from a third party don't form matrimonial property and shouldn't be taken account of in a separation and divorce. The money is ring fenced. However, if the recipient uses the property for marital purposes including paying off the mortgage on the matrimonial home then it is deemed to be converted to matrimonial property and would enter the "pot" to be shared between the parties. It is no longer ring fenced. You do still have an argument against equal sharing, however and that is to argue that the money used to reduce the mortgage was not derived from the income and efforts of the parties and that unequal sharing is justified. Happy to discuss. I hope that helps. Please leave a positive rating so that I am credited for my time.