To apply for a PO Box in Arizona, pick a Post Office and box size on usps.com, complete PS Form 1093, and bring two forms of identification to the counter to pay the fee and pick up your keys. You can reserve online first to lock in the box, but you still have to show up in person for the ID check. Most applicants finish the whole process in a single visit.
The Two IDs You Have to Bring
USPS will not release keys without two valid forms of identification: one with a photo, and one that ties you to a physical address. Both must be current and in your name.1United States Postal Service. PS Form 1093 – Application for Post Office Box Service
Acceptable photo IDs include an Arizona driver’s license or MVD-issued state ID, a U.S. passport or passport card, an alien registration card, a certificate of naturalization, a military or government ID, a university or recognized corporate employee ID, and a NEXUS or Matricula Consular card.
For the second ID, bring something that confirms your address: a current lease, mortgage, or deed of trust; a voter registration or vehicle registration card; or a home or vehicle insurance policy.
Social Security cards, credit cards, and birth certificates are not accepted at all, not even as the secondary document. Applicants get turned away for bringing these regularly, so check what you have before you go.
Choosing a Box Size
USPS offers five sizes, though not every Arizona Post Office stocks all of them.2United States Postal Service. PO Box Sizes
- Size 1 (Extra Small) fits 10 to 15 letters or a couple of rolled magazines.
- Size 2 (Small) holds the same letter volume with room for up to five rolled magazines.
- Size 3 (Medium) is wide enough for large envelopes and magazines to lie flat.
- Size 4 (Large) fits two shoeboxes plus letters, which suits households or small businesses expecting regular packages.
- Size 5 (Extra Large) is built for Flat Rate Boxes and parcels.
If your mail overflows the box on 12 of any 20 consecutive business days, USPS can require you to upgrade to a larger box, add a second one, or switch to Business Mail Pickup (Caller) Service.3United States Postal Service. Domestic Mail Manual D910 – Post Office Box Service
Finding a Location and What It Costs
Three things drive the price: the size you pick, the specific Post Office, and whether you rent for 3, 6, or 12 months.4United States Postal Service. About PO Box Services Boxes in metro Phoenix and Tucson generally cost more than boxes in Flagstaff, Sierra Vista, or Yuma. Post Offices sitting near private mailbox competitors like UPS Store locations are classified as “competitive” and priced differently from Post Offices that are the only mail option in town.
Use the Find USPS Locations tool at usps.com to check what is actually available. Enter your ZIP code, filter for PO Box services, and the site shows which sizes are in stock at each nearby office along with the exact fee for each term. Reserving online holds the box at that price while you finish the paperwork.
Filling Out PS Form 1093
The application is PS Form 1093. You can fill it out digitally as part of an online reservation, or print pages 3 and 4 and complete them by hand before walking in.1United States Postal Service. PS Form 1093 – Application for Post Office Box Service
The form asks for your full name, physical street address, phone number, and email. You will also write down the ID numbers from both documents you plan to present. If the box is for a business, list the business name.
One detail people miss: the form has a space for every person authorized to receive mail at the box and every person who will pick it up. If a family member or employee is not listed, the counter can refuse to hand them your packages later. Add anyone who might come pick up mail before you sign.
Reserving Online vs. Applying at the Counter
The online path starts at usps.com/poboxes. Select your Arizona Post Office, choose a size and rental term, complete the digital Form 1093, and pay with a credit or debit card. You still need to visit the Post Office with both IDs so a clerk can verify you before releasing the keys. Do it soon after paying, because the reservation can be canceled if verification drags on.
Two situations do not work online: applying for Caller Service, and applying for a no-fee box. Both require walking into the Post Office from the start.
If you skip the online step entirely, bring the completed Form 1093 and both IDs to the counter of the Arizona Post Office where you want the box. Cash, check, credit card, and debit card all work. The clerk verifies your ID on the spot and you leave with the keys the same day.
Keys, Deposit, and Lobby Access
Each PO Box comes with two keys and a refundable key deposit. On the 2026 USPS fee schedule, that deposit is $5.50. Losing a key or wanting extras costs an additional duplication or replacement fee. The clerk gives you your assigned box number and shows you where to find it in the lobby.
Many Arizona Post Office lobbies stay unlocked outside counter hours, so you can check your box early or late. A few are open 24 hours, but that is not the rule everywhere. Check the hours posted at your specific location or on that office’s page at usps.com.
When a package will not fit in your box, USPS leaves a slip or a parcel locker key inside instead. The locker key opens a larger compartment nearby; otherwise you pick the package up at the counter during staffed hours.
Keeping the Box and Refunds If You Close Early
Your rental fee is due by the 10th of the month it comes due. If USPS has not received payment by then, the box closes on the 11th and incoming mail starts going back to senders.4United States Postal Service. About PO Box Services The cutoff catches people on 3-month automatic renewal whose card on file has expired, so keep the billing method current.
You also have to keep the information on Form 1093 up to date. If your street address, phone, or email changes, update the form at your Post Office. Not doing so can end your service.
If you cancel before the term is up, the refund depends on which term you bought:5United States Postal Service. USPS Terms and Conditions
- 3-month rental: no refund after activation.
- 6-month rental: 50 percent refund within the first three months, nothing after.
- 12-month rental: 75 percent within the first three months, 50 percent in months four through six, 25 percent in months seven through nine, nothing after month nine.
The 12-month term is the most forgiving if your plans might change. The 3-month term is the least.
Free PO Boxes for Some Arizona Addresses
Some Arizona residents qualify for a no-fee box, which USPS classifies as Group E. You are eligible if your home or business is inside a Post Office’s delivery area and your address is a potential delivery point, but USPS does not actually run carrier delivery to your location. This comes up in parts of rural Arizona where no mail route reaches the door.3United States Postal Service. Domestic Mail Manual D910 – Post Office Box Service
Only one free box per qualifying address, and USPS picks the smallest size that fits your typical volume. A second box or a larger one is available at the regular fee. Residents of hotels, college dorms, military installations, and transient housing do not qualify even where carrier delivery is absent. No-fee applications have to be filed in person.
Using a PO Box as a Business Address
An Arizona PO Box works as a mailing address for a sole proprietorship or small business. You can receive customer payments and business correspondence there, and you can file IRS paperwork using it. If your business address changes to or from a PO Box, the IRS asks you to file Form 8822-B to update its records.6Internal Revenue Service. About Form 8822-B, Change of Address or Responsible Party – Business
A PO Box will not satisfy every requirement, though. Some Arizona registrations, including a Transaction Privilege Tax license, need a physical street address and will reject a PO Box. If your business gets heavy package volume, ask the counter about Caller Service rather than trying to force everything into the largest box.