Separation itself (whether you are living together, married or in a civil partnership) does not affect the terms of any Will you have previously made, so, if your former partner, spouse or civil partner is due to inherit anything from you, they will still do so.
Whether you are married, in a civil partnership or living together, you may want to review and change your Will so you can be sure that what you have goes to the people you want it to when you die.
If you are divorcing or dissolving a civil partnership, on Decree Absolute or dissolution of the civil partnership - see the steps involved – Divorce and the steps involved – civil partners), anything left to spouses and civil partners in existing Wills become invalid, although the rest of the Will still stands. You should therefore review your Will at that stage to make sure it is fully valid and reflects your wishes, as your priorities may have changed.
If you subsequently remarry or enter into a civil partnership, your existing Will lapses so you should then prepare a new Will to reflect your wishes and priorities.
If you have not made a Will before, it is a good idea to make one now, especially if you have children. As well as thinking about their financial security, your Will can also say who you would like to care for your children if you were to die (although this may not necessarily be what happens if there was a dispute). Expect to pay around £75 to £100 for a simple will drawn up by a solicitor, but more if your financial affairs are complex or if you want to plan your affairs to minimise the tax you will pay. See Useful links for details of where to find a solicitor.