If your address is at a mail receiving business, a PMB and a suite are different things. A suite is a unit inside a building. A PMB (private mailbox), or the # sign, marks your box at that business, and Postal Service rules allow only those two box labels.
A commercial mail receiving agency (CMRA) is a business that accepts U.S. Mail for other people as a service. A virtual mailbox at a mail center is one example, and our post on what a CMRA is covers the term in full. The U.S. Postal Service (USPS) sets its addressing rules in Publication 28 and in the Domestic Mail Manual (DMM).
We read Publication 28 sections 213 and 285, its Appendix C2, DMM sections 508 and 602, and a 2000 Federal Register rule on October 30, 2026. We sell virtual mailboxes, and the section before the FAQ covers how we handle box numbers.
Why a suite and a PMB are two different parts of an address
The clearest answer sits in DMM 602, where USPS lists the parts of a complete delivery address. Section 602.1.4.2 gives seven items, labeled a through g. Item b and item e are the two that matter here. Item b reads:
"Private mail box designator and number (PMB 300 or #300)."
Item e reads:
"Secondary address unit designator and number (such as an apartment or suite number (APT 202, STE 100))."
Two other items sit between them, so the box number and the suite number hold separate places in the list. Section 602.1.3 makes the same split in a shorter list. Item b of that section covers the "Private mailbox designator ("PMB" or alternative "#") and number if the mailpiece is addressed to a commercial mail receiving agency (CMRA) address."
Publication 28 section 213 describes the suite side. The section says "Secondary address unit designators, such as APARTMENT or SUITE, are required to be printed on the mailpiece for address locations containing secondary unit designators." Appendix C2 holds the approved list of those designators.
We counted the rows in Appendix C2. The table has 25 rows, from Apartment to Upper, and PMB appears in 0 of them. The words "private," "mailbox" and "box" also appear in 0 rows.
A suite number tells the carrier where a unit is inside a building. A PMB number tells the mail center which customer box gets the piece. In our reading, writing Suite in place of PMB puts your box number in the slot for a building unit and leaves the box slot empty.
| Question | PMB or # | STE, APT or UNIT |
|---|---|---|
| What it points to | A customer's private box at a commercial mail receiving agency | A unit inside a building, such as a suite or an apartment |
| Where USPS defines it | Publication 28 section 285, DMM 508.1.8.3, and DMM 602.1.4.2 item b | Publication 28 section 213 and Appendix C2, and DMM 602.1.4.2 item e |
| Who sets the number | The mail center assigns the box number to the box holder | The building's own unit numbering, and USPS says the correct designator may be shown in its ZIP+4 file |
| Which labels are allowed | Only "PMB" or "#" | The approved designators in Appendix C2 |
| Can both appear in one address? | Yes. A Publication 28 example puts #234 above the street line 10 MAIN ST STE 11 | Yes, when the mail center's building has its own suite |
USPS allows only two labels for a box number
Publication 28 section 285 sets the rule for mail to a CMRA customer:
"Mail sent to an addressee at a CMRA must include either the PMB identifier or the #, followed by the appropriate private mailbox number. Use of any other identifier is prohibited."
Suite is not one of those two labels. We counted words in the body text of section 285. "PMB" appears 5 times. "Suite" appears once, in a list of the mail center's own address parts: "(e.g., rural route box number, suite, # or other term)".
We ran the same count on DMM 508.1.8.3, the CMRA address format section. "PMB" appears 15 times there. "Suite" appears once, again as part of the mail center's building address.
In the texts we read, we didn't find a sentence that says a suite may not be used. USPS names the two labels a box may carry, and Suite is not on that list.
Both elements can share one address. Section 285 shows a four-line example that reads JOE DOE, #234, 10 MAIN ST STE 11, HERNDON VA 22071-2716. In that example, STE 11 is the building's suite and #234 is the customer's box. When the two share one line, section 285 marks "10 MAIN ST STE 11 # 234" as unacceptable and "10 MAIN ST STE 11 PMB 234" as acceptable.
Line-by-line layouts, including the four-line and three-line formats, are in our post on whether your mailing address is a PO Box. For the steps to set up a mailing address for a company, see how to set up a business mailing address.
Why USPS created the PMB label
USPS explained the reason in 2000. A final rule in the Federal Register, 65 FR 49917 (August 16, 2000), describes how box holders addressed mail before the CMRA rules:
"Previously, postal regulations had not prescribed the manner in which mail to CMRA private mailbox holders must be addressed, and many private mailbox holders have used a designation (e.g., "Suite" or "Apartment") along with the street address of the CMRA. This practice implied to senders of mail that the boxholder maintained a physical presence at that location."
The same rule says the original rule "was intended to serve consumer protection interests by providing the public with a means to be aware whether an address represented a physical location." So the PMB label exists to show senders that an address is a box at a mail center. A suite label suggests an office, and the rule names that suggestion as the problem.
The original rule, published on March 25, 1999, required the label "PMB." Industry representatives then told USPS that the label "might adversely affect small businesses." A proposal on March 13, 2000, let box holders use either "PMB" or "#." The Federal Register says that proposal "was intended as a means to balance the consumer and small business interests."
USPS received 20,456 comments on the rule. Of those, 291 comments opposed the option of using either PMB or #. Many came from consumer protection groups, such as state attorneys general. In the rule's words, those groups said "the "#" designation may be confusing to senders of mail, who believe it represents a physical location." The final rule took effect on August 16, 2000, and all parties had to comply by August 1, 2001.
If you want an address that shows a suite and no PMB
A common request online goes like this: someone wants a virtual address with "Suite" in it and no "PMB" or "Box." An honest answer has three parts.
First, a business that receives mail for customers as a service is a CMRA. DMM 508.1.8.1 defines a CMRA as a business that "accepts the delivery of U.S. Mail on behalf of another person or entity as a business service." Mail to its customers needs PMB or # under section 285.
Second, at least one provider help page we read says you can swap PMB for Suite, Apt or Unit when you share your address. The same page says to keep PMB only for USPS paperwork. Section 285 doesn't make that split. Section 285 says "Use of any other identifier is prohibited," and DMM 508.1.8.3 says USPS "may return mail without a proper address to the sender endorsed "Undeliverable as Addressed, Missing PMB or # Sign."" What a returned letter with that kind of endorsement means is in what "insufficient address" means at USPS.
Third, an address with only a suite can be correct when the suite is yours. In our reading, a suite-only address fits when you rent that unit yourself, such as a leased office. Virtual office centers can work differently. At least one virtual office network says on its help page that most of its centers give clients a shared suite number, and some give a PMB. A shared suite belongs to the building, so the suite number alone doesn't mark your box. DMM 508.1.8.1 says office business centers "are considered CMRAs for Postal Service purposes and must comply with the requirements in 1.8." Whether a given center counts as a CMRA is a separate question, and this post doesn't settle it for any one center.
Changing the label also may not hide the address type. In the 2000 rule, USPS said it "will establish methods (toll-free number and/or Postal Service Web site) that can be accessed to determine whether a street address is the location of a CMRA." USPS address data includes a table of CMRA addresses that address software can check. The USPS PostalPro "Guide to Post Office Box Street Addresses (PBSA)" says the DPV CMRA table "identifies addresses that are associated with either a Commercial Mail Receiving Agency or a PBSA." In our reading, the table matches the street address, and the label on the envelope isn't what it reads. Our post on an address flagged as a commercial mail receiving agency explains what happens after a flag.
How Auteur handles box numbers
We sell virtual mailboxes, so this is the seller's view. Auteur is in pre-launch, and your exact street address is assigned the day your city opens. Our address page says: "US mail rules require commercial mail agencies to identify recipient boxes, and we follow those rules; what you print on your letterhead is a street address." The rule for that box label is in DMM 508.1.8.3, which says a CMRA must mark the delivery address of its customers "by the use of "PMB" (private mailbox) or the alternative "#" sign."
The Virtual Business Address receives mail in a business or trade name. Choose it if your letters come addressed to an LLC, a corporation or a DBA (doing business as) name. The Virtual Mailing Address is for personal mail, in individual names only.
Both plans photograph the envelope of every piece, and we open and scan only when you ask, for one flat fee per piece. Henry, our AI assistant, explains each letter you ask us to open. USPS Form 1583 is required before any provider can receive mail for you. Pricing comes by email with the next steps, and our fees and limits are in our fair use policy.
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FAQ
Do I have to put PMB in my address?
If your box is at a commercial mail receiving agency, you need PMB or # before the box number. Publication 28 section 285 says mail to a CMRA customer "must include either the PMB identifier or the #, followed by the appropriate private mailbox number." DMM 602 says mail to a CMRA customer "must be addressed to their private mailbox ("PMB" or "#") number at the CMRA mailing address." Without one of the two labels, USPS may return the mail.
What does PMB mean at The UPS Store?
PMB stands for private mailbox. The UPS Store's mailbox FAQ says: "Your mailing address will be the address of The UPS Store location, with either PMB (private mailbox) or the pound symbol (#) designating your individual box." The FAQ names only those two labels for the box.
Can one address have both a suite number and a PMB?
Yes, when the mail center's building has its own suite. DMM 602.1.4.2 lists the two as separate items, so both can appear in one address. On one line, Publication 28 shows "10 MAIN ST STE 11 PMB 234" as acceptable. The two numbers can't be merged, and DMM 508.1.8.3 gives "10 MAIN ST STE 11-234" as the example of what "is not permissible."
Does USPS ban the word Suite for a private mailbox?
Not by name. Section 285 says the box needs PMB or #, and "Use of any other identifier is prohibited." That rule covers Suite used as the box label. In the texts we read, we didn't find a sentence that bans the word itself. Suite still belongs in the address when the mail center's building has a suite, as in 10 MAIN ST STE 11.
This post explains USPS addressing standards and our own published policy. The post isn't legal advice.
Bottom line
A PMB and a suite are two different parts of a US address. DMM 602.1.4.2 lists the private mailbox designator as item b and the suite or apartment designator as item e. For a box at a mail center, Publication 28 section 285 allows only PMB or #, and "Use of any other identifier is prohibited." A 2000 Federal Register rule says box holders who wrote "Suite" implied a physical presence at the mail center. The same rule says the PMB label was meant to show whether an address was a physical location.
