Notice of intent to sue

How to send a notice of intent to sue — with proof it arrived

A notice of intent to sue is the last letter before a lawsuit. It tells the other side exactly what you claim, what settles it, the date you will file if nothing happens, and where you will file. It is often the letter that ends the dispute — and when it is not, it becomes evidence. That only works if you can prove it was sent, when it arrived, and what it said.

The short answer

1. Write it plainly. The facts with dates and amounts, the claim, the specific remedy, a calendar deadline, and the court you will file in.
2. Check whether a law requires notice first. Some claims cannot be filed until a set number of days after written notice — and a few say exactly how that notice must be mailed. Examples are below.
3. Send it by USPS Certified Mail with a return receipt to the right legal address, so the Postal Service records the mailing date, the tracking history and the signature.
4. Keep the exact letter with the mailing record. Certified Mail proves that an envelope was delivered — not what was inside it. The proof is complete only when the unchanged letter sits next to the receipt.
5. Wait out the deadline, then file. Put the letter and the delivery record in your court file. Many courts ask whether you tried to resolve the dispute first; now you can show it.

What goes in it

1. Heading and parties. Your name and address, the recipient's full legal name, the date. Mark it “Notice of intent to sue” so no one can call it a routine complaint.
2. The facts, in order. What was agreed, what happened, what it cost you. Dates, amounts, invoice or account numbers. No adjectives.
3. The claim. In one sentence: breach of the contract, the unreturned deposit, the unpaid invoice, the defective product.
4. What settles it. A specific amount or a specific act. One number, stated once.
5. The deadline. A calendar date — “by October 15, 2026” — not “promptly”. Ten to thirty days is common; if a statute sets a notice period, give at least that.
6. Where you will file. Name the court: “Small Claims, Superior Court of California, County of Orange.” Specific beats threatening.
7. How to respond. An address, an email, a payment method. Make it easy to say yes.
8. Your signature.

A sample you can adapt

Invented names and numbers. Replace every detail with your own, and remove anything you are not prepared to do.

When the law requires notice before you can sue

For most everyday disputes a notice of intent to sue is good practice, not a legal requirement. For some claims it is required, and skipping it — or sending it the wrong way — can get a case dismissed or cost you damages. Three California examples show how specific these rules get:

• Small claims. California's small claims form tells you that you must ask the defendant to pay before you sue — in person, in writing or by phone. Writing is the version you can prove. Individuals may claim up to $12,500; businesses up to $6,250.
• Consumer claims for damages under the Consumers Legal Remedies Act. Civil Code section 1782 requires written notice at least thirty days before filing, sent by certified or registered mail, return receipt requested. The mailing method is written into the statute.
• Professional negligence claims against a health care provider. Code of Civil Procedure section 364 requires at least ninety days' notice of the intention to sue, stating the legal basis of the claim and the type of loss.

Other states and other claim types — claims against government bodies, construction defects, some insurance and landlord disputes — have their own notice rules and deadlines. If your claim might fall under one, read the rule itself or ask a lawyer before you mail. The letter is cheap; missing a statutory step is not.

Why Certified Mail with return receipt

A notice of intent to sue does two jobs: it gives a last fair chance to settle, and it creates the record a judge will look at. Email can be denied, filtered or “never seen”. Certified Mail gives you a mailing receipt, a Postal Service tracking history and, with a return receipt, the signature of whoever accepted it — or the record that it was refused or left unclaimed, which is evidence too.

What Certified Mail does not give you is proof of the contents. The Postal Service records that an envelope went from you to them; it never sees the letter. If the other side says “that envelope was empty” or “it said something else”, the receipt alone cannot answer. You answer with the exact letter, kept unchanged next to the mailing record.

Doing it yourself at the Post Office

USPS Certified Mail with an electronic return receipt costs about $9.24 to $9.28 in postage and fees at the counter for a one-page letter, plus printing and an envelope. Print two copies, keep one, fill in the Certified Mail form, ask for the return receipt, keep the receipt, and later save the tracking history and signature from usps.com. It works; the weak point is the paper trail, which lives in a drawer.

Questions people ask

Is a notice of intent to sue legally required?

Usually not, but for some claims it is. California's small claims form requires you to ask for payment before filing, consumer damages claims under the Consumers Legal Remedies Act need thirty days' written notice by certified or registered mail, and professional negligence claims against health care providers need ninety days' notice. Check the rule for your claim and state.

How long should I give them?

Ten to thirty days is common. If a statute sets a notice period, give at least that, and state the deadline as a calendar date.

Does Certified Mail prove what my letter said?

No. It proves mailing and delivery of an envelope. Keep the exact letter, unchanged, with the mailing record — Piloxa stores the document and its fingerprint together with the tracking and signature for this reason.

What if they refuse the letter or never pick it up?

The tracking record shows the attempted delivery and the refusal or return. That is still evidence that you sent notice to the right address on a specific date.

Can a letter written by ChatGPT or Claude be used?

Yes — who typed the words does not matter; what matters is that the facts are accurate and you stand behind them. Read every line before you send it, and correct anything the assistant got wrong.

Primary sources

• California Judicial Council form SC-100 (Plaintiff's Claim), rev. January 1, 2026
• California Civil Code section 1782
• California Code of Civil Procedure section 364
• USPS Postal Explorer: Certified Mail and return receipt

Legal and postal references last reviewed September 10, 2026. Requirements vary by claim and jurisdiction.

Other letters people send certified

• Demand letter
• Send a certified letter
• Mail a letter your AI wrote
• Letter to a landlord
• Cease and desist
• What Certified Mail proves