An inside address is the block of recipient information near the top of a formal business letter: the person’s name, their title, their organization, and the full mailing address, stacked on single-spaced lines between the date and the salutation. It mirrors what appears on the envelope so that once the envelope is discarded, the letter itself still shows who it was sent to and where. That matters for filing, for contract records, and for any correspondence you might later need to prove was sent to the right person.
What to Include, Line by Line
The inside address follows a fixed top-to-bottom order. The same sequence the USPS recommends for delivery addresses works here:
- Recipient’s name, with a courtesy title (Mr., Ms., Dr.) when you know which one applies. If you’re unsure, the full name without a title is safer than guessing.
- Professional title on its own line directly below the name. Short titles can share the name’s line, separated by a comma.
- Organization name, written out in full. Use the official name rather than a nickname, unless the abbreviation is the legal name.
- Street address, including any suite, floor, or apartment number. If the suite number won’t fit on the street-address line, place it on the line above, not below.
- City, state, and ZIP code on the final line, with a comma after the city and the two-letter state abbreviation before the ZIP.
The USPS specifies one space between city and state and two spaces between the state abbreviation and the ZIP code for mail processing.1United States Postal Service. Two-Letter State and Possession Abbreviations Most business letters use a single space before the ZIP and nobody notices, but the two-letter state abbreviation itself is non-negotiable for anything moving through the mail.
Where It Sits on the Page
The inside address goes directly below the date, with one blank line between them. After the last line of the address, leave another blank line before the salutation. The pattern runs: date, blank line, inside address, blank line, salutation. Writers sometimes add space to balance a short letter, but one line above and one line below is the default.
The address block is always left-aligned, no matter which letter format you use. In full block style, every element of the letter sits flush left. In modified block style, the date and closing shift toward the right, but the inside address stays on the left margin.2United States Postal Service. Business Mail 101 – Delivery Address Within the block itself, use single spacing so the lines read as one compact unit.
Punctuation and Capitalization
Modern business letters use minimal punctuation in the inside address. No periods at the ends of lines. The only standard marks are the comma between city and state, periods inside abbreviations like “Mr.” or “Inc.,” and a period after “St.” or “Ave.” if you abbreviate the street type. Some writers use open punctuation style, which drops punctuation from the salutation and closing, but the city-state comma stays.
Capitalize the recipient’s name, professional title, organization name, and street address the same way you would write them anywhere else. The USPS actually recommends all capital letters with no punctuation for mail that will run through automated sorting, but that convention is for the envelope, not the inside address of the letter.2United States Postal Service. Business Mail 101 – Delivery Address
Special Addressing Situations
Attention Lines
When the letter is officially directed to an organization but you want a specific person to handle it, use an attention line. The USPS places the attention line at the top of the address block, above the company name rather than below it.2United States Postal Service. Business Mail 101 – Delivery Address Many business letters write “Attn:” followed by the person’s name on the first line, then the company name on the next. The attention line routes the letter internally; the organization is still the formal recipient.
In Care Of
Use a “c/o” line when the intended recipient doesn’t have their own address at the destination, or when mail is being sent to them through another person or company. The intended recipient’s name goes on the first line, “c/o” followed by the intermediary’s name on the second, then the street address and city line below. For example:
Jane Doe
c/o XYZ Company
123 Oak Street
Wilmington, NC 28401
The salutation addresses the intended recipient, not the intermediary.
Professional Credentials
Credentials like Esq., CPA, or Ph.D. follow the name, separated by a comma. When someone holds a doctoral credential, skip the courtesy title: write “Jane Doe, Ph.D.” rather than “Dr. Jane Doe, Ph.D.” Pick one. For attorneys, “Esq.” replaces “Mr.” or “Ms.” in formal correspondence, so “John Smith, Esq.” stands on its own without a courtesy title in front.
Military Addresses
Mail to military personnel uses APO (Army Post Office), FPO (Fleet Post Office), or DPO (Diplomatic Post Office) in place of a city, along with the two-letter code AA for Armed Forces Americas, AE for Armed Forces Europe, or AP for Armed Forces Pacific. Include unit and box numbers if assigned. Do not include a city or country name in a military address; adding one can route the letter through a foreign postal system and cause significant delays.3USPS.com. How Do I Address Military Mail
Why Accuracy Is Worth the Extra Minute
Nearly 25 percent of all mailpieces carry some kind of addressing error, from a missing apartment number to a wrong ZIP code to a bad directional like “East” when the address is “West.” Some still get delivered, at extra cost and delay; others don’t arrive at all.2United States Postal Service. Business Mail 101 – Delivery Address Directional words deserve particular care: 100 North Main Street and 100 South Main Street can sit on opposite sides of a city.
The stakes climb when the letter has legal weight. Commercial contracts routinely include notice provisions requiring written communication to a specific person at a specific address, and some jurisdictions demand strict compliance. A letter sent to the wrong address or the wrong person can fail to trigger contractual notice even when the other side actually received it. For a demand letter, a termination notice, or a cure notice, check every line of the inside address against the notice clause before you send.
Inside Addresses in Email
Standard business emails don’t carry an inside address. The recipient information is already in the “To” field, and a salutation alone is enough. The exception is formal correspondence transmitted electronically: a resignation letter sent as an attachment, a formal proposal, or legal correspondence. The attached document follows paper-letter formatting, inside address included. The body of the email itself doesn’t need one.