Priority Mail Express: Rates, Delivery Times & Guarantee

Priority Mail Express is the fastest domestic shipping service from USPS, delivering in one to three days with a money-back guarantee if the package arrives late. Retail postage starts at $33.00 at the Post Office counter, or $28.80 if you buy your label online through Click-N-Ship. Every shipment includes $100 of insurance, real-time tracking, and delivery 365 days a year, including Sundays and federal holidays.

How Fast It Delivers

Delivery takes one, two, or three days depending on the origin and destination ZIP codes and the day USPS accepts the package. Unless you have a special end-of-day agreement, packages are guaranteed to arrive by 6:00 PM on the scheduled delivery day.¹ Some destinations offer a 10:30 AM delivery option for an added fee.²

Sunday and holiday delivery costs an extra $12.50 on top of standard postage.³ If you can wait, selecting guaranteed delivery on the next regular business day avoids the surcharge.¹

What It Costs

Pricing is based on weight and distance zone, with a separate set of flat rate envelope prices. Buying postage online instead of at the counter unlocks commercial rates, which start at $28.80 versus the $33.00 retail floor.⁴ That’s roughly a 13% discount for printing your own label.

Flat Rate Envelope Prices for 2026

With flat rate envelopes, you pay one price regardless of weight (up to 70 pounds) or zone:

Flat Rate Envelope (12½” × 9½”): $33.25 retail / $28.80 commercial
Legal Flat Rate Envelope (15″ × 9½”): $33.50 retail / $29.10 commercial
Padded Flat Rate Envelope (12½” × 9½”): $34.15 retail / $29.35 commercial

There are no flat rate boxes for this service. Boxes are priced by weight and zone.³

Size and Weight Limits

Whether you use a USPS envelope or your own packaging, the package cannot exceed 70 pounds or 108 inches in combined length and girth.⁵ Length is the longest side; girth is the distance around the thickest part, calculated as width × 2 + height × 2. Anything over the limit won’t qualify for the service and will be returned or reclassified.

Signature Options and Your Receipt

When you create the label, you choose between Signature Required and Waiver of Signature. Signature Required means the carrier must obtain the recipient’s signature before releasing the package. Waiver of Signature authorizes the carrier to leave it in a secure spot like a mailbox or doorstep without anyone present.⁵ For valuable or sensitive items, Signature Required creates a documented chain of custody.

Keep the mailing receipt. USPS is required to issue one with an acceptance timestamp, and it’s the document you’ll need to prove your guaranteed arrival time and to file a refund claim if the package runs late.⁵

Insurance Included

Every shipment comes with $100 of insurance covering loss, damage, or missing contents.⁶ You can buy additional coverage on merchandise up to a $5,000 total.⁷

Coverage limits vary by contents. Non-negotiable documents like business records are capped at $100 regardless of how important they are to you. Merchandise can be insured up to $5,000 with added coverage. In a catastrophic loss event, such as a fire affecting many packages at once, total indemnity is capped at $5,000 across all affected items with no more than $100 per piece.⁷ If you’re shipping several high-value items, spreading them across separate mailings reduces exposure to any single loss event, though the per-piece cap still applies.

Tracking and the Money-Back Guarantee

Every shipment gets a unique tracking number printed on the receipt. You can follow it on the USPS website or subscribe to text and email updates. Tracking shows each scan point: acceptance, in transit, out for delivery, and delivered.

How to Claim a Refund for Late Delivery

If your package misses its guaranteed delivery time, you’re entitled to a full postage refund. The refund policy is governed by DMM Section 604.9.5, and USPS measures against the guaranteed arrival time printed on your receipt.⁸

The filing window depends on whether you added extra services:

Standard Priority Mail Express with no extra services: file between 2 and 30 days after the mailing date.
Priority Mail Express with extra services: file between 30 and 60 days after the mailing date.

You can submit the claim through the USPS online refund portal or in person at a Post Office with your original receipt.⁸

When the Guarantee Is Suspended

USPS has suspended the guarantee during past holiday seasons. During the 2025 holiday period, refunds were suspended for one-day shipments mailed between December 22 and December 25 if delivery was attempted or completed within two business days of the mailing date.⁹ Similar suspensions have occurred in other years. If you’re shipping around the holidays and relying on the guarantee, check the USPS newsroom for any current adjustments.

Mailing Tax Returns and Legal Documents

Any item sent through the U.S. Mail is considered filed on time if it’s properly addressed, has sufficient postage, and is postmarked by the deadline.¹⁰ The advantage of Priority Mail Express for tax returns and other time-sensitive filings is the timestamped receipt, which provides clear proof of when the item entered the postal system.

Private carriers like FedEx and UPS also qualify under the timely-filing rule, but only for specific service levels the IRS has designated.¹¹ Pick the wrong FedEx or UPS service and the mailing doesn’t count. With USPS, any mail class satisfies the postmark rule.

What You Can’t Ship

Some items are banned outright from USPS. Others can be shipped but only under specific conditions.

Prohibited Items

The following cannot be mailed domestically through any USPS service, including Priority Mail Express: ammunition, explosives, gasoline, liquid mercury, strike-anywhere matches, and marijuana regardless of state-level legality.¹² Senders are responsible for checking Publication 52 before bringing questionable items to the counter.

Ground-Only Hazardous Materials

Perfume, hand sanitizer, and loose lithium batteries all contain restricted contents that keep them off aircraft. Since most Priority Mail Express moves by air, these items ship by ground and may take longer than the standard one to three days.¹² Lithium batteries installed in or packed with a device can travel by air; loose batteries cannot, and quantity and marking rules apply.¹³ Dry ice is permitted as a refrigerant, capped at 5 pounds per package by air, and requires specific hazard labeling and paperwork.¹⁴

Cremated Remains

USPS is the only shipping carrier that accepts cremated remains, human or pet, and Priority Mail Express is the only mail class allowed for them.¹² Use either the USPS Priority Mail Express Cremated Remains box or your own container with Label 139 affixed to all six sides.¹⁵

Shipping Internationally

The domestic guarantee and pricing described here don’t apply to international shipments. Priority Mail Express International is a separate service reaching roughly 180 countries in three to five business days, with its own pricing, size restrictions, and customs requirements.¹⁶ Country-specific prohibitions also apply, so check USPS country conditions for your destination before shipping.

1
United States Postal Service. Domestic Mail Manual 213 – Priority Mail Express Prices and Eligibility
2
Postal Explorer. Priority Mail Express
3
United States Postal Service. Notice 123 – January 2026 Price Change
4
United States Postal Service. Postage Rates and Prices
5
Postal Explorer. Domestic Mail Manual 113 – Retail Mail Priority Mail Express
6
United States Postal Service. Insurance and Extra Services
7
Postal Explorer. Filing Indemnity Claims for Loss or Damage
8
United States Postal Service. Request a USPS Refund – Domestic
9
USPS News. Priority Mail Express Refund Policy Adjusted for the Holidays
10
USPS. Mailing Your Tax Return
11
Internal Revenue Service. Private Delivery Services
12
United States Postal Service. Shipping Restrictions and HAZMAT
13
USPS Postal Explorer. Publication 52 – Appendix C – USPS Packaging Instruction 9D
14
United States Postal Service. Publication 52 – Appendix C – USPS Packaging Instruction 9A
15
USPS. New Shipping Process for Cremated Remains
16
United States Postal Service. Priority Mail Express International – Rates and Features