They do different jobs. A will does nothing while you're alive. If you lost capacity tomorrow, your family would have to apply to the Court of Protection, which takes months and costs considerably more than putting a power of attorney in place now.

There are two types of power of attorney, property and finances, and health and welfare. Each person needs their own of each, so a couple doing both types registers four documents and pays four fees.

You can, and for genuinely simple situations it may be fine. It goes wrong when there's a second marriage, a business, property abroad, a child who needs protecting, or someone likely to challenge it. The cost of getting it wrong lands on the people you leave behind.

Two near-identical wills, one for each of a couple, usually leaving everything to each other and then to the children. It's the most common arrangement and it's priced as a pair.

You can update a will whenever you like. Small changes can be made by codicil, but it's often cleaner to redo it. Worth reviewing after a marriage, a divorce, a birth or a house move.