Guides · reviewed 2026-09-04

How to write a demand letter (and why you send one first)

Legal information, not legal advice. Results depend on the facts of your case.

Legal information, not legal advice. This guide and our free tools give legal information. They do not give advice about your case. A licensed lawyer can give legal advice.

The answer

A demand letter tells the defendant what they owe, why, and the date to pay. A clear demand letter can end the dispute before you pay a court fee. It also becomes your first exhibit.

You do not need a demand letter before you file a claim. It is still a good first step.

The letter does not stop the 2-year limitation clock. The clock runs while you wait for a reply.

What to do

  1. Write the date, your name, and the defendant's full legal name and address.
  2. State the amount owed. Show the calculation: invoices, payments, and the balance.
  3. State the facts in order: what you agreed, what happened, and the dates.
  4. List your documents: invoice numbers, the contract date, and key emails.
  5. Set one clear date to pay. 10 business days is common. Our tool sets that date: /demand-letter.
  6. State your next step: a claim in Small Claims Court for the amount plus interest and costs.
  7. Do not threaten. State only the legal step you will take.
  8. Send the letter so you can prove it: email plus registered mail or courier.
  9. Keep a copy and every delivery receipt.

For a loan with no due date

For a loan payable on demand, the 2-year clock starts on the first day the borrower fails to pay after your demand. Your demand letter is that demand. Keep proof of the date it was delivered. Read: suing a friend for a loan.

Deadlines and fees

  • A demand letter costs $0.
  • The letter does not stop or pause the 2-year limitation clock.
  • Only a signed written acknowledgment of the debt, or a part payment, restarts the clock.
  • If the defendant does not pay, file your claim: $108.
  • You can claim interest from the day the claim arose.

Common mistakes

  • Do not write a rough amount. Write the exact number and show the calculation.
  • Do not set a vague deadline. Write one date.
  • Do not threaten a criminal complaint, a regulator, or a bad review. State only the claim you will file.
  • Do not send the letter and then wait for months. The 2-year clock runs.
  • Do not send it without proof. Use email plus registered mail or courier, and keep the receipts.

When to get a lawyer

A lawyer can send the demand letter for you. Get advice if the amount is large. Legal services provided by Mithril Law — Jonathan Kleiman, licensed Ontario lawyer.

Free tools