PO Box
A locked, numbered mailbox at a post office where the recipient collects mail rather than receiving carrier delivery to a physical street address.
PO Boxes (Post Office Boxes) are rented compartments within a USPS facility. They provide a stable mailing address for individuals and businesses that lack street delivery, move frequently, or prefer the privacy of a separate address. Box sizes range from small (letter-size) to extra-large (parcel capable), and rental fees vary by location and size.
The USPS sorts PO Box mail directly into the appropriate compartment at the facility, bypassing carrier routes entirely. This often means earlier availability than street-delivered mail. Some facilities offer Package Pickup Service, where parcels too large for the box are held at the counter.
In addressing, the PO Box number replaces the street address on the delivery line. The USPS recommends using the format 'PO BOX 1234' without periods. Some online retailers and shipping carriers (UPS, FedEx) do not deliver to PO Boxes, which has led the USPS to offer Street Addressing for PO Boxes at select locations.