I don't have any choice in France - under the Code Napoleon it is impossible to disinherit your children and the percentage left to other relations is strictly defined. Expats who have stepchildren get into awful problems unless they take advice before they buy a property.
In spite of the actions of one daughter, I would still want to leave my flat (my only asset) equally to both of them, but there are people who have not seen a child for thirty years, or who know that the money would go on drink/drugs/gambling and still they cannot disinherit them. There is some talk of a change in the law but things move slowly. A friend has had to give up her life in France because she needs to set up a trust fund for a son with severe mental health problems.
I think many UK solicitors will offer to draw up a fairly simple will for about fifty pounds which seems a small price to pay for expert guidance
They will usually act as executors for a fee based on the amount of time involved, unlike banks which tend to charge a percentage of the estate regardless of how much work is involved. (Steer clear of banks whenever possible!)
I hope all gransnetters have taken the advice to make a folder with full details of your financial affairs, insurances, pensions, passwords, preferred funeral arrangements, medical intervention choice, etc. and given instructions to somebody trustworthy to open it when you die. And, of course, none of you are in ignorance of your partner's affairs, are you?