Answer

PMB means Private Mailbox, the USPS term for the mailbox number a CMRA assigns you. SnapMailbox uses a similar format but calls its version the SMB#. This number must be used in your mailing address to ensure your mail is uploaded to your account. Your SMB# also functions as your account number and is unique to you.

General information

USPS treats a company that takes U.S. Mail for others as a CMRA.

A CMRA is a private mail company. It is not USPS, a Post Office, your home, or your work site.

USPS Form 1583 must be approved before the company can handle your mail.

Service steps to consider

Choose the address and plan that match the people and mail volume you expect.

Complete Form 1583 with current details and accepted ID.

Use the exact address and SMB# shown in the account.

How SnapMailbox can help

SnapMailbox operates as a full-service virtual mailbox provider built around exactly this kind of question. Every account starts with a real street address, plus a unique SMB# that's used on all your mail and packages. Once USPS Form 1583 is verified, your online dashboard begins showing a photo of the outside of each item as soon as it arrives, so you always know what's waiting before deciding what to do with it. From there, you can request scanning, forwarding, storage, or secure shredding for individual pieces, or set standing rules so recurring mail is handled automatically. Support is available directly from your account if anything about this needs a closer look, and the same tools apply whether you're checking your mailbox daily or just once in a while.

Important limits

A virtual mailbox does not replace your home, work site, or registered agent when a rule calls for one of those addresses.