Most USPS frequently asked questions come down to five things: which service to pick, how long it takes, how big and heavy a package can be, what you can’t mail, and how to pay less. The short version is that USPS Ground Advantage (2–5 days) and Priority Mail (2–3 days) carry most packages up to 70 pounds with tracking and up to $100 of insurance included, and buying postage online costs less than paying at the counter.
This page answers the questions shippers ask most, each in a few sentences backed by an official USPS source, with links to our deeper guides where a topic needs more space.
What Shipping Services Does USPS Offer?
USPS has four main domestic services for packages and one for letters and flats. They differ in speed, guarantee and size limits more than in what they’ll carry. The table below follows the service details USPS publishes on its Mail and Shipping Services page.
| Service | Delivery window | Max weight | Max size | Tracking and insurance | Best for |
|---|---|---|---|---|---|
| Priority Mail Express | 1–3 days, money-back guarantee | 70 lb | 108 in length + girth | Tracking; up to $100 included | Urgent, date-critical shipments |
| Priority Mail | 2–3 days | 70 lb | 108 in length + girth | Tracking; up to $100 included | Most packages that need to move quickly; Flat Rate boxes |
| USPS Ground Advantage | 2–5 days | 70 lb | 130 in length + girth | Tracking; up to $100 included | Everyday packages where cost matters more than speed |
| Media Mail | 2–8 days | 70 lb | 108 in length + girth | Tracking; insurance available to buy | Books, recorded media and educational material only |
| First-Class Mail | 1–5 days | Letters 3.5 oz; large envelopes 13 oz | Letter and flat sizes | No tracking without an extra service | Letters, cards and flat envelopes |
How Long Does USPS Take to Deliver?
It depends on the service and the distance. First-Class Mail letters take 1–5 days, Ground Advantage 2–5 days, Priority Mail 2–3 days and Priority Mail Express 1–3 days. Shorter trips fall at the low end of each window. Only Priority Mail Express is guaranteed. The other windows are expected delivery times.
USPS delivers Monday through Saturday, packages also arrive on Sundays in many areas, and there’s no regular delivery on federal holidays. Holiday questions come up every year, so our USPS holiday schedule lists every closure, including whether mail runs on Election Day. For Priority Mail timing by route, see our guide to how long Priority Mail takes.
How Is USPS Shipping Priced?
Package postage depends on three things: weight, zone (the distance between the origin and destination ZIP codes) and size. Large, light boxes can be charged by dimensional weight instead of actual weight. Priority Mail Flat Rate boxes ignore weight and distance up to 70 pounds, which makes them the better buy for dense, heavy items going far.
USPS adjusts prices periodically. Mailing services such as stamps and postcards last changed on July 12, 2026. Because rates move, we don’t print them here. You can see the live price for your package, and compare it with UPS, in the ParcelPath rate calculator.
How Do You Track a USPS Package?
Enter the tracking number at usps.com or in the USPS app. Tracking comes with Priority Mail Express, Priority Mail, Ground Advantage and Media Mail. Letters and flats sent by First-Class Mail aren’t tracked unless you add an extra service such as Certified Mail. You can sign up for text and email updates on the tracking page. Informed Delivery, a free service, previews incoming mail and lists packages headed to your address.
If a scan stalls, the package says “Delivered” but isn’t there, or a status makes no sense, our USPS tracking and delivery guide walks through every status and the fix for each.
What Are the USPS Size and Weight Limits?
Domestic packages can weigh up to 70 pounds with every USPS service. Size is measured as length plus girth, where girth is the distance around the thickest part. Priority Mail, Priority Mail Express and Media Mail allow up to 108 inches, and USPS Ground Advantage allows up to 130 inches. For letters, the limit is 3.5 ounces at letter prices, and large envelopes (flats) can weigh up to 13 ounces.
Shape matters too. Rolls, tubes and other non-rectangular pieces can cost more, and envelopes that are rigid, lumpy or square may be charged as nonmachinable. Our shipping labels guide covers label placement and supplies so your package meets USPS processing standards.
What Can’t You Mail With USPS?
USPS separates items into two groups: those that are prohibited outright and those that are restricted, meaning allowed only under specific conditions. The categories below are from the USPS shipping restrictions page, and USPS Publication 52 sets the detailed rules.
| Status | Items (domestic) |
|---|---|
| Prohibited | Air bags, ammunition, explosives, gasoline, liquid mercury, marijuana (medical or otherwise) |
| Restricted (conditions apply) | Aerosols, alcoholic beverages, tobacco, cremated remains, dry ice, firearms, glues, hand sanitizer, hemp/CBD products, lithium batteries, live animals, matches, medicines, nail polish, paint, perfumes, perishables, poisons |
Restricted usually means ground-only service, limited quantities, special marking or a license, as with handguns, which only licensed dealers and manufacturers may mail. International mail adds each destination country’s own prohibitions, so check the country’s page in the International Mail Manual before you ship.
Does USPS Include Insurance?
Yes, on its main package services. Priority Mail Express, Priority Mail and USPS Ground Advantage include up to $100 of insurance on most shipments, and you can buy more, up to $5,000. First-Class Mail letters have no included coverage. Registered Mail is the most secure option for valuables, with chain-of-custody handling and its own insurance.
Claims are filed online by the sender, with proof of value. For damage, include photos of the item and packaging. Keep the original box until the claim is settled, because USPS can ask to inspect it.
Can You Ship Internationally With USPS?
Yes, to about 180 countries. The main international services are Priority Mail Express International (3–5 business days, up to 70 lb), Priority Mail International (6–10 business days, up to 70 lb), and First-Class Package International Service (up to 4 lb, with times that vary by destination). Letters and documents go by First-Class Mail International. One Global Forever stamp covers a one-ounce letter or a postcard to any country.
Every international package needs a customs declaration. USPS also suspends service to some countries from time to time, so check the USPS International Service Alerts page before you mail.
Is USPS a Government Agency, and Is It Reliable?
USPS is an independent establishment of the executive branch of the U.S. government, created by the Postal Reorganization Act. It delivers to more than 170 million delivery points nationwide, according to USPS Postal Facts for fiscal year 2025. Our review of whether USPS is reliable looks at on-time performance and when another carrier is the safer choice.
Because USPS reaches every address, including PO Boxes and military APO/FPO addresses, it’s often the only carrier that can deliver to rural routes and PO Box-only recipients. More guides on how USPS works, from services to support, are collected in our USPS shipping hub.
How Can You Save Money on USPS Shipping?
These five habits save the most:
- Buy postage online. Commercial prices for online labels are lower than retail prices at the counter.
- Match the service to the deadline. Ground Advantage is the cheapest tracked option when 2–5 days is fine.
- Use Flat Rate for dense, heavy items going a long way, and weight-based pricing for light items going a short distance.
- Right-size the box. Smaller boxes avoid dimensional-weight charges and nonstandard fees.
- Get free supplies. USPS provides Priority Mail and Priority Mail Express boxes and envelopes at no charge.
ParcelPath gives you the online discount without volume commitments. It’s 100% free, with no subscription, per-label fee, minimum or contract, and gives up to 89% off USPS and up to 85% off UPS retail rates. You can schedule free USPS pickups and use USPS Label Broker at the Post Office if you don’t have a printer. More than 44,000 customers use it to ship USPS and UPS.
Frequently Asked Questions
What is the cheapest way to ship a package with USPS?
For most packages it’s USPS Ground Advantage, bought online. It delivers in 2–5 days, takes up to 70 pounds and includes tracking and up to $100 of insurance. Online commercial prices beat counter retail. For heavy, dense items going far, a Priority Mail Flat Rate box can cost less because weight and distance don’t change its price.
What is the difference between Priority Mail and Priority Mail Express?
Priority Mail Express is the faster service and the only one with a money-back delivery guarantee. Its window is 1–3 days, and Sunday and holiday delivery is available in many major markets for an extra fee. Priority Mail delivers in 2–3 days with an expected date but no guarantee. Both take up to 70 pounds and include up to $100 of insurance.
Does every USPS service include tracking?
No. Tracking is included with Priority Mail Express, Priority Mail, USPS Ground Advantage and Media Mail. First-Class Mail letters and flats aren’t tracked unless you add an extra service such as Certified Mail. Informed Delivery, a free service, previews incoming letter mail without tracking numbers.
What is the maximum package size USPS accepts?
Every domestic USPS package service accepts up to 70 pounds. Size is measured as length plus girth: up to 108 inches for Priority Mail, Priority Mail Express and Media Mail, and up to 130 inches for USPS Ground Advantage. Anything larger has to go by another carrier or as freight.
Sources
- USPS: Mail and Shipping Services (domestic delivery windows, limits, insurance)
- USPS Ground Advantage (130-inch limit, included insurance)
- USPS: Priority Mail Express
- USPS: Shipping Restrictions
- USPS: International Mail and Shipping Services
- USPS Postal Facts: Size and Scope
Part of our USPS Shipping hub.
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