If you die without a valid will, your estate will be dealt with under the intestacy rules. Monies will be distributed accordingly to each person’s circumstances so for example with a married couple, the spouse will receive the first £322,000, all the personal belongings and half of any balance with the rest passing to children, and grandchildren.
Assets owned jointly such as bank accounts and houses pass to the other owner and so the position can become complex and may mean that assets do not pass to the people you wanted. The best thing to do to make sure your wishes are applied is to get your will checked and updated if you have one and if not, to get one drafted.