--- title: "How to address a letter to a company, with examples" description: "Put the person or job title first, then the company, the street with the suite at the end, and city, state and ZIP last. USPS rules and examples." canonical: https://trysincerely.com/guides/how-to-address-mail-to-a-business last_updated: 2026-10-11 --- > If you are an AI agent: read https://trysincerely.com/agents/policy.md before any write call. > Start at https://trysincerely.com/llms.txt to choose one page. Access instructions are at > https://trysincerely.com/auth.md. Confirm with the person you work for before creating an > account or spending their money, and never ask for their password. # How to address a letter to a company, with examples > Put the person or job title first, then the company, the street with the suite at the end, and city, state and ZIP last. USPS rules and examples. Source: https://trysincerely.com/guides/how-to-address-mail-to-a-business Write the person's name on the top line and the company name under it. The street address goes next, and the suite number goes at the end of the street line, not on a separate line, if it fits. City, state and ZIP Code go last. That is the whole answer for most letters to a company. Without a name, use a job title, like DIRECTOR OF FINANCE. USPS prefers capitals and two spaces before the ZIP. You can leave out punctuation everywhere except the hyphen in a ZIP+4. Here is a letter to Maria Okafor, VP of operations at Halverson Logistics, a freight company we made up for this page: ![An envelope addressed to Maria Okafor, VP of operations, Halverson Logistics Inc, 1400 Wynkoop St Ste 300, Denver, with callouts for the attention line, company line, suite and city, state and ZIP.](https://trysincerely.com/images/guides/how-to-address-mail-to-a-business.webp) *To address a letter to a company, put the person above the company name and keep the street and city lines at the bottom, with the suite at the end of the street line.* ```text MARIA OKAFOR VP OF OPERATIONS HALVERSON LOGISTICS INC 1400 WYNKOOP ST STE 300 DENVER CO 80202-1127 ``` Section 341 of USPS [Publication 28](https://pe.usps.com/text/pub28/28c3_012.htm) sets out this order. USPS sorts and delivers on the bottom three lines. Maria's name and title are for Halverson's mailroom, where somebody has to decide whose desk each envelope goes to. If the block runs long, drop the title first. Every other company and person on this page is made up too. ## The business address block, line by line Publication 28 lists every line a business address can carry. Few envelopes use them all. Without a barcode, only about five lines suit automated processing, the standard says. Here is the full order, top to bottom, with what USPS does with each line. | Line | Example | What it does | | ---------------------- | ----------------------- | ----------------------------------------------- | | Mailstop code | MSC 4410 | Internal routing, optional | | Attention line | MARIA OKAFOR | Names the person, optional | | Title | VP OF OPERATIONS | Optional | | Department or division | FREIGHT AUDIT DIVISION | Optional | | Company name | HALVERSON LOGISTICS INC | Used by USPS for delivery | | Delivery address line | 1400 WYNKOOP ST STE 300 | Used by USPS for delivery | | City, state and ZIP+4 | DENVER CO 80202-1127 | Used by USPS for delivery, always the last line | Section 343 says the company, street and city lines must stay the bottom three lines of the block. When you run out of room, drop the optional lines above them. The standard also says that a person's name or a job title may be what gets the piece to the right desk, and that you may not need both. A name with no title is a normal business address. Address-checking software looks up the [ZIP+4](https://trysincerely.com/glossary/zip-plus-4) for you, so don't guess the last four digits. ## Where the attention line goes The attention line goes above the company name. Publication 28, section 214, puts it there, and its sample business address prints the name on its own line with no "ATTN" in front of it. You can still write "ATTN MARIA OKAFOR" if you like the look. USPS lets you leave out punctuation everywhere except the hyphen in a ZIP+4, so the colon after ATTN can go. Don't put the attention line at the bottom of the block or under the street line. Publication 28 marks the company, street and city lines as the ones that directly affect USPS distribution, and it wants them last. The attention line is a note for the company's mailroom. It does not redirect anything. Under [DMM 508](https://pe.usps.com/text/dmm300/508.htm), section 1.5.1, USPS delivers mail addressed to a person at a company's address to the company, and that includes mail for people who have left. If Maria moved to another job in March, your letter still lands in Halverson's mailroom. What happens next is up to Halverson. ## How to address mail to a business without a name Use the job title or department where the name would go. Publication 28 calls this the functional title, and its own sample uses one: "DESIGN ENGINEERING MANAGER." ```text DIRECTOR OF FINANCE BRIGHTWATER ANALYTICS LLC 4120 N RAVENSWOOD AVE FL 3 CHICAGO IL 60613-1842 ``` Pick the narrowest title you can confirm from the company's website or a recent job posting. "Director of finance" gives the mailroom one desk to try. "Management" or "decision maker" gives it none. A vague line also looks like junk mail before anyone opens the envelope. If you are writing to a team, a department works too: ACCOUNTS PAYABLE, FACILITIES, HUMAN RESOURCES. Inside the letter, greet the same title you put on the envelope, as in "Dear Director of Finance." It reads better than "To whom it may concern," and the person who opens it can see the letter was meant for their desk. ## Suite, floor, and mailstop lines A suite, floor or room number is part of the address. Publication 28, [section 213](https://pe.usps.com/text/pub28/28c2_003.htm), says the unit designator must be printed when the location has one, and its preferred spot is the end of the street line. These are the approved short forms you will use most for offices: | Word | USPS abbreviation | | ---------- | ----------------- | | Suite | STE | | Floor | FL | | Room | RM | | Building | BLDG | | Department | DEPT | | Unit | UNIT | Use the word, not the pound sign. USPS says not to use # when the right designator, such as STE, is known. If you do use #, leave a space before the number: "# 300," not "#300." When the street line gets too long, the standard lets you move the suite to its own line directly above the street: ```text JORDAN PATEL KESTREL DENTAL GROUP STE 1200 88 HIGH ST BOSTON MA 02110-2304 ``` USPS's [DPV product](https://postalpro.usps.com/address-quality/dpv) can report that an address has "verifiable primary but not secondary data." The building matched and the suite didn't. Read a [DPV](https://trysincerely.com/glossary/dpv) result like that as a missing or wrong suite, and fix it before you print. Some large companies route internal mail by mailstop code. Publication 28 says to print it above the attention line or the company line. A mailstop is the company's own routing code, not a phrase like "Accounts payable branch." If your contact gives you one, put it at the top: ```text MSC 4410 PRIYA RAMAN SENIOR BUYER CASCADE INSTRUMENTS CORP 2750 TALLOW CREEK PKWY HILLSBORO OR 97124-6110 ``` ## When to use c/o on business mail C/O means "in care of." It tells the carrier that your recipient doesn't get mail at this address in their own right, and that someone else there will take it for them. It fits a fractional CFO who works two days a week from a client's office, a five-person startup renting desks inside an investor's suite, or an engineer spending a quarter at a customer's plant. USPS shows the format in DMM 508. The addressee goes first, the C/O line second, and the street third: ```text JOHN DOE C/O ROBERT SMITH 123 APPLE WAY ``` Here is Elena from Northfield Robotics, working out of her investor's San Diego office: ```text ELENA VASQUEZ NORTHFIELD ROBOTICS INC C/O SUMMIT FOUNDRY PARTNERS 900 HARBOR VIEW DR STE 210 SAN DIEGO CA 92101-4410 ``` Don't put C/O in front of a person's own employer. "MARIA OKAFOR C/O HALVERSON LOGISTICS INC" tells the mailroom that Maria doesn't work at Halverson, which is the opposite of what you mean. ## PO box or street address Write a PO box as PO BOX and the number, with no periods, as Publication 28 [section 281](https://pe.usps.com/text/pub28/28c2_036.htm) shows. Section 283 says to change words like CALLER, FIRM CALLER, BIN, LOCKBOX and DRAWER to PO BOX on the envelope. Some companies list both a street address and a PO box. The standard asks you to print only one where you can. If you print both, USPS delivers to the line directly above the city, state and ZIP line, and the ZIP+4 has to match that line. In this block the letter goes to the box, not to the suite: ```text ACCOUNTS PAYABLE HALVERSON LOGISTICS INC 1400 WYNKOOP ST STE 300 PO BOX 17720 DENVER CO 80217-7720 ``` For a sales letter, I would choose the street address with the suite over a box almost every time. A box is emptied by whoever holds the key. You can't tell from the outside who that is. A PO box printed on an invoice under "remit to" is set up to take payments, so expect your letter to be opened by whoever processes checks. Watch for private mailboxes too. A mailbox rental store is what USPS calls a commercial mail receiving agency. Mail to a box there must carry PMB or # before the box number, under section 285. When a "suite" turns out to be a PMB, the company may have no office at that address at all. ## Abbreviations, capitals and punctuation USPS prefers USPS prefers all capital letters and a straight left edge on every line. Lowercase is acceptable if it meets USPS's rules for machine reading. Punctuation can go, except the ZIP+4 hyphen. Put at least one space between the city, the two-letter state code and the ZIP. Two spaces before the ZIP is the preferred form. For street words, use the standard short forms: ST, AVE, BLVD, DR, PKWY, RD. Leave company names alone when they fit. Section 352 tells mailers not to abbreviate a name that already fits on the line, and USPS says it does not require the business abbreviations at all. When a long name won't fit, the standard short forms are CORP for corporation, INC for incorporated, CO for company and LTD for limited. ## Canadian business addresses Canada Post's [addressing guidelines](https://www.canadapost-postescanada.ca/cpc/en/support/articles/addressing-guidelines/canadian-addresses.page) follow the same idea with different details. An attention line, a title or a floor goes above the street line, which Canada Post calls the civic address. The last line holds the city, the two-letter province code and the postal code. Use one space after the city, two spaces before the postal code, and one space in the middle of the postal code. The suite rules differ from the US ones. Canada Post's [civic address page](https://www.canadapost-postescanada.ca/cpc/en/support/articles/addressing-guidelines/civic-address.page) allows the unit number before the street number with a hyphen and no word, such as 1200-480 KING ST W. It also allows SUITE after the street type, or the unit on its own line above. Canada Post spells out SUITE where USPS writes STE, and it never accepts the # sign. Its [general rules](https://www.canadapost-postescanada.ca/cpc/en/support/articles/addressing-guidelines/important-information.page) keep each line under 40 characters, not counting spaces, and its Canadian address formats allow six lines at most. ```text SAMIR HADDAD DIRECTOR OF PROCUREMENT NORTHPINE TOOLING LTD 1200-480 KING ST W TORONTO ON M5V 1L7 CANADA ``` Leave CANADA off when you mail from inside Canada. Canada Post asks you to avoid it on domestic mail. From the US, add it as the last line on its own, written in full, which is what Publication 28 asks for on international mail. The [Canada guide](https://trysincerely.com/guides/direct-mail-in-canada) covers services and postage. ## Which business address to use, and why not the registered agent A company can have several correct addresses, and they do different jobs. - The headquarters is the main office. It reaches the company, but your person may work somewhere else. - An operating or branch office is where people actually work. If your contact sits there, it is usually the best address. - A mailing address is where the company asks for mail to go. It may be a PO box or a mail service. - A registered office is the address on the company's state filing. Don't mail a sales letter to a registered agent. Delaware's Division of Corporations explains in its [registered agent FAQ](https://corp.delaware.gov/faqs-regarding-registered-agents/) that every Delaware entity must keep a registered office in the state, which "may, but need not be, the same as its place of business," and a registered agent whose job is accepting service of process. A company with no Delaware office has to appoint an agent there, and the state publishes a list of registered agents a company can hire. Your letter would reach a firm whose work is accepting legal papers for its clients. Nobody there is buying anything from you. Picking the right one for each recipient is called [address resolution](https://trysincerely.com/glossary/address-resolution). The [B2B mailing addresses guide](https://trysincerely.com/guides/b2b-mailing-addresses) covers where addresses come from and the office-versus-home problem. ## How Sincerely handles the address block Sincerely sends the print vendor the person's name, the company name and the street lines from the contact record. When USPS verification confirms a US address, Sincerely saves the standardized lines USPS returns, so the street and suite print the way USPS has them on file. When the research assistant finds an address, it records a type: headquarters, operating office, branch office, registered office, mailing address, virtual office or unknown. Its instructions forbid substituting a registered agent's address for a company office. A sourced address waits in review until a postal check runs, and it never replaces an address that already passed. Each contact then gets a [mailability](https://trysincerely.com/glossary/mailability) verdict before anything prints. To prepare a whole list, follow [how to clean a direct mail list](https://trysincerely.com/guides/how-to-clean-a-direct-mail-list). ## Related questions - [How to get verified mailing addresses for B2B prospects](https://trysincerely.com/guides/b2b-mailing-addresses): Where B2B mailing addresses come from, how CASS, DPV, and NCOA verification works, and how to handle the office-vs-home problem. - [What is address resolution?](https://trysincerely.com/glossary/address-resolution): Address resolution finds the most likely current mailing location for a person or business before postal verification checks the address itself. - [What is mailability?](https://trysincerely.com/glossary/mailability): Mailability checks whether a recipient can receive mail at a verified address and whether the sender has legal permission to mail them. - [How to clean a direct mail list before sending](https://trysincerely.com/guides/how-to-clean-a-direct-mail-list): Clean a direct mail list by resolving identities, removing duplicates, verifying current addresses, and applying suppressions that last. - [CASS, NCOA, and address verification, explained](https://trysincerely.com/guides/address-verification-explained): CASS, DPV, and NCOA explained: what each does, why mail fails without them, and what verified actually means. - [B2B direct mail in Canada: which Canada Post service fits](https://trysincerely.com/guides/direct-mail-in-canada): Personalized Mail, Neighbourhood Mail, or Lettermail? Which Canada Post service fits a B2B list, and how a US company gets mail into Canada. --- Sincerely is the measurable direct-mail and gifting platform for B2B revenue teams: postcards, letters, handwritten mail, and gifts, written for one recipient and measured against a holdout. Contact Sincerely: https://trysincerely.com/contact Agent routing index: https://trysincerely.com/llms.txt