What is Priority Mail Express?

Priority Mail Express is the fastest domestic shipping service USPS offers. As of September 16, 2026, USPS commits to delivery in 1 to 3 days by 6 PM local time at the destination, backed by a money-back guarantee, 7 days a week to most U.S. addresses and PO Box addresses. Which of those three days you get depends on the origin ZIP Code, the destination ZIP Code, and when USPS accepts the package. USPS shows the committed date before you pay.

Next-day delivery exists between some ZIP Code pairs when the package is dropped off early enough, but it is not the nationwide promise. If the delivery date matters, treat 1 to 3 days as the standard and look up your pair before you buy the label.

How to check your delivery date before you ship

USPS publishes a Service Commitments tool on usps.com. Enter the ZIP Code you are shipping from, the ZIP Code you are shipping to, and the date and time you plan to mail the package. It returns the scheduled delivery day, whether USPS can offer the money-back guarantee for that pair, and the drop-off times and locations that meet it.

Acceptance time is the variable most people miss. USPS states that the time of day it accepts the item, along with other factors, determines whether it arrives in 1, 2, or 3 days, and that drop-off cutoffs vary by Post Office location. Acceptance points include a Post Office, a Contract Postal Unit, a Priority Mail Express collection box, a letter carrier, or a scheduled Package Pickup.

What it costs

Current USPS prices took effect July 12, 2026. Retail Priority Mail Express starts at $35.65 at a Post Office, which is the price for a package up to half a pound in Zone 1. Everything else is priced by weight and zone across zones 1 through 9, so a 1 lb box costs $35.90 retail in Zone 1 and $62.80 retail in Zone 8. If you are not sure which zone applies, read how USPS shipping zones work.

Commercial prices are lower than retail. USPS offers them through Click-N-Ship and through PC Postage providers such as Stamps.com, Pitney Bowes, Endicia, and EasyPost. The same 1 lb Zone 8 package is $55.79 at the commercial rate.

Flat Rate Envelopes are the cheapest predictable option and ship up to 70 lbs anywhere in the U.S. at one price:

Other price rules to check before you print a label:

• Maximum weight is 70 lbs, and maximum combined length and girth is 108 inches.
• Packages larger than 1 cubic foot are billed on dimensional weight, which is length times width times height in inches divided by 139.
• Nonstandard fees: $4.50 for 22 to 30 inches long, $21.00 for more than 30 inches long, $35.00 for more than 2 cubic feet, and $4.50 for a nonstandard shape or material such as a tube or a can. USPS Flat Rate packaging is exempt from these fees.
• Sunday and holiday delivery is available in many major markets for an additional fee. It is not included in the base price and not offered everywhere.

For a side-by-side with regular Priority Mail, which USPS lists at 2 to 3 days with no money-back guarantee, see Priority Mail compared with Priority Mail Express.

What is included

• USPS Tracking.
• Up to $100 of insurance with most shipments. The package must carry an applicable USPS shipping label to qualify, and you can buy additional coverage above $100.
• A proof of delivery signature record, if you request it when you buy the label.
• Free Package Pickup from your home or office.
• Delivery 7 days a week, 365 days a year, with limited exceptions, to most U.S. addresses and PO Box addresses.

If USPS misses the date

USPS refunds the postage, plus the Sunday or holiday premium if you paid it, when the package was not delivered, not attempted, or not made available for pickup by the guaranteed date and time on your receipt. Only the sender can file, so keep the mailing receipt or the customer copy of the label. The filing window depends on whether you bought an extra service:

File online at usps.com, or take the receipt or label copy to any Post Office and complete PS Form 3533. A denied online request can be appealed online within 30 days of the denial.

Three scan events count as meeting the commitment even if nobody received the package, so they defeat a refund claim:

• "Attempted delivery": the carrier went to the address and no one was available to accept the item.
• "Arrival at Pickup Point": for PO Box and Firm Caller addresses, the item was available for pickup.
• "Forwarded": the actual delivery address differed from the label.

USPS notes this is not a complete list. Refunds are also denied when the delay was outside USPS control, such as an incorrect ZIP Code or address, a strike, or cancelled flights.

One exclusion catches shippers off guard. Since August 1, 2023, USPS no longer processes guaranteed-service refund requests for Priority Mail Express items addressed to or from Alaska and Hawaii. Loss claims on those shipments are still processed.

When Priority Mail Express is worth it

Use it when the delivery date is the reason for the shipment and the Service Commitments tool returns a guaranteed date for your ZIP pair. Documents, replacement parts, and last-minute orders a customer has already paid extra for fit that description. Run the price before quoting a customer, because a Flat Rate Envelope at $31.11 commercial and a heavy box to Zone 9 sit at opposite ends of the range.

Skip it when the tool returns no guarantee for the pair, when the shipment goes to or from Alaska or Hawaii, or when a 2 to 3 day Priority Mail window meets the deadline. If you are also pricing FedEx for a next-morning commitment, see what FedEx Priority Overnight covers.

The commitment starts from the time USPS accepts the package, not the time the order comes in. If Simpl's ecommerce fulfillment service handles your orders, postage is included in the flat per-order rate, and orders received before 12pm CT ship the same day by UPS, USPS, or FedEx.

Common questions

Is Priority Mail Express overnight?

Not everywhere. The USPS standard is 1 to 3 days by 6 PM local time. Next-day delivery is available between some ZIP Code pairs when USPS accepts the package early enough, and the Service Commitments tool shows the scheduled day before you buy.

What happens if Priority Mail Express is late?

The sender can request a refund of the postage, plus the Sunday or holiday fee if purchased, when the package was not delivered, attempted, or made available for pickup by the guaranteed date and time. File 2 to 30 days after the mailing date, or 30 to 60 days if you bought an extra service. An "Attempted delivery" scan counts as on time, and shipments to or from Alaska and Hawaii are excluded from guarantee refunds.

Does Priority Mail Express deliver on Sunday?

In many major markets, for an additional fee. Sunday and holiday delivery is not included in the base price and is not available everywhere. If USPS misses a paid Sunday delivery, the refund includes that fee.

Is Priority Mail Express insured?

Most shipments include up to $100 of insurance along with USPS Tracking, as long as the package carries an applicable USPS shipping label. Additional insurance above $100 can be purchased.

Can Priority Mail Express go to a PO Box?

Yes. USPS delivers Priority Mail Express to most U.S. addresses and PO Box addresses. For a PO Box, an "Arrival at Pickup Point" scan by the committed time counts as meeting the guarantee.