15/10/2026
Legally, she’s still his wife.
Separation on its own doesn’t change anything when it comes to inheritance. Unless they were divorced, or had a formal judicial separation through the courts, the law treats your mum exactly the same as any other husband or wife.
If your dad didn’t leave a Will, the intestacy rules apply. As his spouse, your mum would usually inherit his personal belongings, a large fixed sum and half of anything left over. You and any siblings would share the rest. If his estate is modest, she could inherit everything.
If he did leave a Will, that decides who inherits. If he left everything to you, your mum may still be able to bring a claim against the estate as his spouse. The court would look at how long they’d been apart, their finances and what’s fair.
And if your dad had a new partner, they could be left with nothing at all unless he made a Will.
Separation is often seen as the end of a marriage. In law, it isn’t. If you’ve separated and haven’t divorced, updating your Will is one of the most important things you can do.