A will sets out legally significant instructions. A letter of wishes can explain the personal thinking around them. Used carefully, the letter helps the people dealing with your affairs understand your priorities without filling the will with details that may change frequently.
The distinction matters. A wishes letter is generally guidance, not a substitute for a valid gift, guardianship appointment or trust provision. If you want a direction to have legal effect, obtain advice on where and how it should be recorded.
Explain what people may not know
For parents, a letter might describe a child's routines, important relationships, educational needs or cultural traditions. For an executor, it might explain where useful records are held or why a particular personal possession matters to someone.
Funeral preferences can also be recorded separately, although those wishes should be readily accessible before the estate paperwork is reviewed. Avoid hiding the only copy inside a sealed bundle that nobody expects to open promptly.
Keep it consistent
Read the letter alongside the will. If the will leaves an item to one person but the letter suggests someone else should receive it, the mismatch can create disappointment and confusion. The letter should not appear to change the legal document informally.
Similarly, a wish that trustees use funds in a particular way must fit the powers and duties established by the trust. A complicated arrangement needs professional drafting rather than an attempt to control it through an informal note.
Write with the reader in mind
Use calm, clear language. Explain priorities without trying to anticipate every possible future event. A guardian or executor may need flexibility, and a long list of rigid personal instructions can make a difficult role harder.
Date the letter and review it when circumstances change. Make clear which version is current. Keep confidential security information, such as account passwords and recovery codes, in a separate secure system.
Where a letter explains a sensitive decision, particularly an exclusion or unequal provision, discuss it with a solicitor. Careless or inaccurate statements may aggravate a dispute rather than resolve it.
A useful letter sounds like considered guidance from you. It should make the legal plan easier to understand and carry out, while leaving the legally effective decisions in the documents designed for that purpose.
Sources and further reading
General information, not advice on your individual circumstances. Laws and tax rules can change; check the linked official guidance and obtain professional advice where needed.