Letters, wills, and advance directives: what each one does

A letter to your family can carry your feelings, but it has no legal force. Who gets your property, and what medical care you'd want if you can't speak for yourself, are handled by formal documents. The rules differ by country and by state, so this guide covers what each document is for and how to get started, not the legal fine print.

Based on laws and official guidance as checked on 2026-10-20. Rules and screens can change, so check the latest official guidance before you act.

First, what each one does

Document	What it covers	Legal weight
A letter to your family	Your feelings, memories, where things are	Not legally binding
Will	Who gets your property; in many places, who you'd want to care for children who are still minors	Valid only if made the way local law requires
Living will	Which treatments you would or wouldn't want, such as CPR, a ventilator, or tube feeding, if you can't speak for yourself	Recognized in many places when signed the way local rules require
Health care proxy	Who makes medical decisions for you when you can't	Same as above; also called a health care power of attorney or health care agent

“Advance directive” is the umbrella term for the last two. In many places, the living will and the health care proxy are parts of a single form.

Wills: what usually matters

Each country and state sets its own rules for a valid will. A few things come up almost everywhere:

It's in writing and signed by you.
It's dated, and it's clear which version is the most recent.
In many places, it's signed in front of witnesses, often two, who generally shouldn't be people inheriting from you.
Some places accept a will written entirely in your own handwriting; many don't. Don't count on it without checking.

Big life changes, like marriage, divorce, a new child, or moving to another state or country, are good times to review your will.

Advance directives: your wishes for medical care

A living will records what you'd want in situations such as a terminal illness or permanent unconsciousness: whether to be resuscitated, put on a ventilator, or given tube feeding.
A health care proxy names one person, plus a backup if you like, to speak for you. Choose someone who knows your wishes and can follow them under pressure.

For people who are already seriously ill, doctors may also use a separate medical order, such as a do-not-resuscitate (DNR) order. Your doctor can tell you whether that applies to you.

How to get started

Ask your doctor or hospital for the advance directive forms used where you live. Health departments, hospitals, and legal aid groups often offer them for free.
Talk with the person you'd like as your health care proxy, and make sure they're willing.
Sign the forms the way they require, usually in front of witnesses or a notary.
For a will, talk with a local lawyer, or a notary in countries where notaries handle wills. Bring a list of what you own and who you'd like it to go to.
Give copies of your advance directive to your doctor and your proxy, and tell your family where the originals are.

Afterward

Tell your family where the documents are, or who's keeping them.
Write a letter explaining why you decided what you did. It has no legal force, but it helps your family understand what you were thinking as they carry out your wishes.
For your own situation, talk with a local lawyer or notary, or with your doctor or hospital.

FAQ

Is a will I record on my phone, as audio or video, valid?

Generally, no. Most places require a will to be in writing and signed in a specific way, and a recording doesn't meet that. A few places make narrow exceptions, and the rules vary, so check with a local lawyer. A recording can still be a good way to tell your family what you were thinking, alongside a proper will.

Can my letters in Sayahead serve as a will?

No. Letters and notes you leave in Sayahead don't have the legal effect of a will. The app's Legal Next Steps page points you toward the formal steps and helps you keep track of which wishes you've already handled with formal documents.

Do I need both a living will and a health care proxy?

Many people have both, and in many places they're on the same form. A living will covers the situations you can foresee; a proxy can handle the ones you can't. Your doctor can help you decide what fits your situation.

Sources and fact-check

This guide is general information, not legal, medical, or financial advice. For your own situation, talk to a qualified professional. Laws and platform features change, so rely on the latest version of the official pages below.

If you spot something wrong or out of date, email us at [email protected] and we will correct it.