Have you made a will? Chances are that you haven't – but that you mean to. We tend to assume that we won't die without making one. Maybe the truth is that we assume we won't die. But it's estimated that one in three UK citizens does die without making a will. And it seems that half of all of those aged 45 or over have yet to get round to it too.

If you haven't, you're not alone. US president Abraham Lincoln and artist Pablo Picasso both died intestate. But here are five reasons why it's better to make sure you've left a legal will behind you.

1. Your partner

You might assume that if you die your partner will get everything. In fact, if you're not married or in a civil partnership there's no legal provision for your partner to inherit and they'd have to make a claim on the estate in order to benefit. They'd probably have to pay a solicitor for their advice. And even then the claim may not succeed.

If you are married the amount your other half can inherit is limited by law. If you don't have children, they'll get your personal possessions, the first £400,000 of your estate tax-free, and half of the rest. The other half will be shared by your parents if they're still alive, if not by your siblings. If you have no surviving parents or siblings, your partner will get everything.

If you have children, your partner will receive your personal possessions, the first £250,000 of your estate tax-free, and a life interest in half of the rest of the estate – which will pass to your children when your partner dies. The other half of your estate will go to your children.

2. Your children

Your surviving children will share your estate if you have no partner and die without a will. If any of your children have died leaving children themselves, then their share will pass to their children - your grandchildren. But if you have dependent children and no partner - or your partner dies too - you'll have to specify in your will who looks after them and what arrangements are made for their future. Otherwise it'll be down to the courts to decide.

3. You decide who gets what

You might have a treasured object, a piece of jewellery, say, or a painting that you'd like a friend to have. To make sure they get it, you'll have to specify it in your will. The same goes for bequests to charities, or if you want to leave items or money beyond your immediate family.

4. The hassle factor - and avoiding costly disputes

Sorting out the estate of someone who's died without a will can be enormously laborious and time-consuming. First-line responsibility for sorting it out will go to your partner - the person who's probably most affected by your death. By leaving a will you can appoint additional executors who can give support and may be better equipped to deal with the situation. And any disputes arising from your lack of will are sure to become expensive when solicitors are taken on to deal with them.

5. Inheritance tax

If you leave everything to your partner in your will, they usually won't have to pay any inheritance tax, however large the estate. If you leave money to others, the first £325,000 is tax-free, but inheritance tax of 40% has to be paid on bequests above this amount. By making a will you can arrange your affairs to minimize the amount of inheritance tax that's liable to be paid on your estate.

Making a will

You can write your own will - as long as you are aged 18 or over, are mentally capable and have your signature be witnessed and signed by two witnesses. But to ensure there are no later problems, it's advisable to consult a solicitor or will writer. Before you do that, you'll need to make a list of what you own, decide who you want to benefit, who you want to look after children under 18, and who your executors will be.

And finally…

Once you've made a will – which must be witnessed by two people – it's recommended that you keep it a copy in a safe place, such as with your solicitor or with your executor, and then update it every five years – or after major life changes, such as the birth of children, a marriage or a divorce.

- Get professional assistance with writing a will »

Source: www.direct.gov.uk