To format a legal letter correctly, follow a fixed top-to-bottom sequence: sender information and date, recipient block and salutation, a “Re:” reference line, the body, a formal closing with signature, and any enclosure or cc notations. Use block-style paragraphs, one-inch margins, and a standard 12-point font. Add protective markings only when they actually apply, and deliver the letter in a way that lets you prove it arrived.
The conventions below apply whether you’re a lawyer or a non-lawyer, though some situations call for a licensed attorney.
The Order of Elements, Top to Bottom
Legal correspondence has an expected shape. Skipping parts or shuffling them signals inexperience to anyone who reads this kind of mail regularly.
Sender Block and Date
Start with the sender’s contact information at the top of the page. On behalf of a firm or company, use official letterhead showing the organization’s name, address, phone, and email. As an individual, type your full name and contact details in the same position.
Two lines below the sender block, place the date. Spell out the month: “January 15, 2026,” not “1/15/26.” Numeric-only dates get misread, especially when international parties are involved.
Recipient Block and Salutation
Below the date, include the recipient’s full name, professional title, organization, and complete mailing address. Get every detail right; a misspelled name or wrong title undermines credibility before the reader reaches the substance.
Use a formal salutation followed by a colon, not a comma: “Dear Ms. Chen:” or “Dear Mr. Garcia:”. If you don’t have a name, “Dear Sir or Madam:” works, but a named addressee is stronger.
The Reference Line
Between the salutation and the body, add a “Re:” line telling the recipient immediately what the letter concerns. In legal correspondence, this usually includes a matter name or number. Pending litigation might read “Re: Johnson v. Apex Industries, Case No. 2025-CV-4831.” An insurance matter might read “Re: Claim No. 48291, Property Damage at 120 Oak Street.” Firms often have a standard format, so check before you invent your own.
Body
Open with one or two sentences stating why you’re writing and what you want. Use the middle paragraphs to lay out facts, legal basis, or supporting points in logical order. Close the body with a clear statement of the action you expect and a deadline for response.
One main point per paragraph. If three separate issues are crowding into a single block of text, break them apart.
Closing, Signature, and Notations
End with a professional closing. “Sincerely” and “Very truly yours” are the standard choices. Leave enough space below the closing for a handwritten signature, then type your full name and title underneath. Under the Uniform Commercial Code, a signature can be made by hand or by machine and may include any name, mark, or symbol adopted with the intent to authenticate the writing.1Legal Information Institute. U.C.C. 3-401 – Signature
If you’re attaching documents, add an “Enclosures” notation below your typed name listing what’s included. If other people are receiving copies, add a “cc:” notation with their names.2The Hartford. What Is the Enclosure Notation in a Business Letter?
Page Layout
The visual presentation of a legal letter has been essentially stable for decades. Courts, opposing counsel, and government agencies expect it, and departures look sloppy.
Use a traditional serif font like Times New Roman or a clean sans-serif like Arial at 12-point. Set one-inch margins on all four sides. Single-space within paragraphs, and leave a blank line between paragraphs rather than indenting the first line. This block style is the default for professional legal correspondence.
For letters that run past one page, number every page after the first. Many offices place the number centered at the bottom, though bottom-right is also acceptable. On subsequent pages, add a header or footer with the recipient’s name, the date, and the page number. Pages get separated when letters are scanned, faxed, or copied, and the identifying line prevents confusion.
Protective Markings
Legal letters often carry sensitive content the sender doesn’t want used against them later. Two markings exist for that purpose, and using them correctly matters.
“Without Prejudice” for Settlement Talks
When you’re negotiating a resolution or making a settlement offer, mark the letter “WITHOUT PREJUDICE” at the top. The label invokes a legal principle that keeps the letter’s contents out of evidence in court, on the theory that parties can’t negotiate honestly if every concession might be read aloud to a jury.
Federal Rule of Evidence 408 provides the statutory backbone. It prohibits using evidence of compromise offers and negotiations to prove the validity or amount of a disputed claim, and its legislative history makes clear that a party can protect statements made during settlement talks by expressly labeling them as hypothetical or “without prejudice.”3Legal Information Institute. Federal Rules of Evidence Rule 408 – Compromise Offers and Negotiations Don’t put this marking on every letter you send. It applies only to genuine settlement discussions, and overuse can lead a court to disregard it entirely.
Privileged and Confidential Communications
Letters between an attorney and client should be marked “PRIVILEGED AND CONFIDENTIAL — ATTORNEY-CLIENT COMMUNICATION” at the top. That puts anyone who receives the letter on notice that its contents are protected. If the letter reflects legal strategy or analysis, adding “ATTORNEY WORK PRODUCT” reinforces the protection.
The label alone doesn’t create privilege where none exists. The communication must actually be between an attorney and client for the purpose of obtaining or providing legal advice. Courts have held that routine use of privilege disclaimers on non-privileged correspondence can dilute their effectiveness when you actually need the protection to hold.
Citing Legal Authority
Legal letters frequently reference statutes, regulations, or court decisions. Sloppy citations suggest you haven’t read the law you’re relying on, so the format matters.
A federal statute citation has three parts with no punctuation between them: the title number, “U.S.C.” for United States Code, and the section number with any subsection designations. A provision of the Social Security Act, for example, appears as 42 U.S.C. § 405(c)(2)(C)(ii). If the statute has been recently amended, add the year of the compilation in parentheses after the section.4Law.Cornell.Edu. Statute Citations – Most Common Form
For court cases, The Bluebook is the standard reference. For practitioner documents like legal letters, the Bluepages section governs rather than the Whitepages used in law review articles.5The Bluebook Online. Quick Style Guide A typical citation includes the case name in italics, the volume number, the reporter abbreviation, the first page of the opinion, any specific pages you’re referencing, the court, and the year in parentheses: Jackson v. Metro. Edison Co., 348 F. Supp. 954, 956–58 (M.D. Pa. 1972).
When you’re writing to a non-lawyer, don’t assume they’ll parse a citation on sight. A short lead-in helps: “Under the Supreme Court’s decision in [case name], employers are required to…” is more useful than dropping a cite and moving on.
Signing the Letter
Not every legal letter needs a wet ink signature. The federal Electronic Signatures in Global and National Commerce Act (ESIGN Act) provides that a signature or record cannot be denied legal effect solely because it’s in electronic form, as long as the transaction involves interstate or foreign commerce.6Office of the Law Revision Counsel. 15 U.S. Code 7001 – General Rule of Validity
For an electronic signature to hold up, the signer must show clear intent. Typing a name, drawing a signature with a mouse, or clicking a clearly labeled acceptance button can all qualify. All parties should receive a fully executed copy, and the electronic record must be stored in a way that allows accurate reproduction later.
Electronic signatures don’t cover everything. The ESIGN Act specifically excludes wills, trusts, adoption and divorce documents, and certain transactions governed by the Uniform Commercial Code. When you’re unsure whether an electronic signature is sufficient, use a handwritten one and scan it.
Delivering the Letter With Proof
How you send a legal letter can matter as much as what it says. In many contexts, you need to prove the letter was delivered, and “I mailed it” won’t cut it.
Certified Mail With Return Receipt
USPS certified mail is the standard for legal correspondence requiring proof of delivery. The return receipt (the green card signed by the recipient) creates a record courts routinely accept. As of January 2026, certified mail costs $5.30 per item on top of regular postage, a physical return receipt adds $4.40, and an electronic return receipt costs $2.82.7United States Postal Service. USPS Notice 123 – January 2026 Price Change For time-sensitive matters, hand delivery with the recipient signing an acknowledgment of receipt is another option.
Email is increasingly accepted, especially between attorneys who have agreed to electronic service. If you send a legal letter this way, request a read receipt and attach the letter as a PDF rather than pasting the text into the email body. The PDF preserves formatting and signature exactly as intended. Keep the sent message and any delivery or read receipts.
Certificate of Service
When a letter relates to pending litigation, you may need to attach a certificate of service: a short statement at the end of the document confirming that you sent a copy to the other party. Federal rules require that a certificate of service specify the date and method of delivery.8Legal Information Institute. Federal Rules of Civil Procedure Rule 5 – Serving and Filing Pleadings and Other Papers A typical certificate reads: “I certify that on [date], I served a copy of this letter on [name] by [certified mail/hand delivery/email] at [address].” Sign it and include it as the last element of your letter.
Keep a Complete Record
Keep a full copy of every legal letter you send, including enclosures, the signed version, and proof of delivery. If you sent it by certified mail, staple the returned receipt to your copy. If you sent it by email, save the sent message and any confirmations. These records are your evidence that the communication happened, and you may need them months or years later. Store both a physical copy and a digital backup.
When Format Isn’t Enough
Format handles presentation. It doesn’t tell you whether the letter should be sent in the first place, or whether the position it takes is sound. Every state prohibits the unauthorized practice of law, which generally includes interpreting statutes, advising on the likely outcome of litigation, or drafting documents whose legal effect requires specialized knowledge to determine.
If your letter involves a complex contract dispute, threatens specific legal action you’re not sure you can follow through on, or turns on how a statute applies to your facts, consult an attorney. A well-formatted letter that misstates the law can hurt your position more than help it.