Priority Mail vs First Class: Which USPS Service to Use

Priority Mail vs First Class comes down to what you’re sending. First-Class Mail is USPS’s service for letters, postcards and large envelopes up to 13 ounces, delivered in 1 to 5 days without tracking unless you add an extra service. Priority Mail is a package service for up to 70 pounds, with delivery in 2 to 3 days, USPS Tracking and up to $100 of insurance included. The old First-Class Package Service no longer exists: USPS replaced it with Ground Advantage in July 2023.

What happened to First-Class Package Service?

On July 10, 2023, USPS announced the launch of USPS Ground Advantage and retired First-Class Package Service, Retail Ground and Parcel Select Ground in the same move. Ground Advantage took over the lightweight-parcel role First-Class Package used to fill and extended it to packages up to 70 pounds, with delivery in 2 to 5 days.

That means older advice comparing “Priority Mail and First Class” for packages is out of date. Today, “First Class” refers to First-Class Mail for letters and flat envelopes, and the package-side comparison is Priority Mail against Ground Advantage, which our guide to USPS Priority Mail vs Ground Advantage covers in full.

What are the key differences between Priority Mail and First-Class Mail?

The two services are built for different mail. First-Class Mail is for paper: letters up to 3.5 ounces and large envelopes (flats) up to 13 ounces. Priority Mail is for packages and heavier documents, with tracking and insurance included.

Size matters as much as weight for First-Class Mail. A large envelope that’s rigid, not rectangular, uneven in thickness or over the size limits is charged package prices and goes by Ground Advantage instead. Our explainer on First-Class Mail covers the size rules in detail.

Should you send documents by First-Class Mail or Priority Mail?

For ordinary letters, bills and cards, First-Class Mail is the default and by far the cheaper option. It has no tracking on its own, so for important papers add an extra service. Certified Mail gives you a mailing receipt and delivery record, and a Certificate of Mailing proves the date you sent it.

Priority Mail makes sense for documents when you need tracking and insurance built in, or when the papers are too thick or heavy for a large envelope. The Priority Mail Flat Rate Envelope (12½” x 9½”) ships for one price anywhere in the US up to 70 pounds, which suits contracts, portfolios and stacks of paperwork.

What replaced First Class for light packages?

USPS Ground Advantage is the service that replaced First-Class Package for small parcels. It uses ounce-based price tiers for packages under 1 pound (up to 4, 8, 12 and 15.999 ounces), then prices by the pound up to 70 pounds. It includes USPS Tracking and up to $100 of insurance, and delivers in 2 to 5 days.

For a light package, the real choice is therefore Ground Advantage for the lowest postage or Priority Mail for faster delivery and flat rate boxes. If you’re sending books or other qualifying educational materials, USPS Media Mail is a slower, lower-cost alternative. Both Priority Mail and Ground Advantage show progress in USPS Tracking.

When should you use Priority Mail instead of First Class?

Use First-Class Mail for anything that fits in a standard letter or flat envelope and doesn’t need tracking: letters, cards, invoices and flat paperwork. Use Priority Mail when you’re sending a package or a document that needs speed, tracking and insurance, or when a flat rate box makes a heavy item cheaper to ship. Our guide to how much it costs to ship a Medium Flat Rate Box explains when flat rate pricing pays off.

For packages that can wait a couple of extra days, Ground Advantage usually costs less than Priority Mail. The USPS shipping calculator guide walks through how weight, zone and size set the price, and our overview of USPS services and shipping options compares every tier.

ParcelPath sells USPS Priority Mail and Ground Advantage labels at up to 89% off, plus UPS labels at up to 85% off, with no subscription, no per-label fee and no minimums. To see the difference for your package, compare Priority Mail and Ground Advantage rates in the ParcelPath calculator.

Frequently Asked Questions

Does USPS still offer First-Class Package Service?

No. USPS retired First-Class Package Service when it launched USPS Ground Advantage, announced on July 10, 2023. Ground Advantage now handles lightweight parcels, with ounce-based price tiers under 1 pound, tracking, up to $100 of insurance and 2-to-5-day delivery. First-Class Mail continues for letters, postcards and large envelopes.

What is the weight limit for First-Class Mail?

First-Class Mail letters can weigh up to 3.5 ounces, and large envelopes (flats) up to 13 ounces. Anything heavier, or a large envelope that’s rigid, lumpy or oversized, is charged package prices and ships by Ground Advantage or Priority Mail instead. Priority Mail accepts up to 70 pounds.

Is Priority Mail faster than First-Class Mail?

Not always. USPS lists First-Class Mail at 1 to 5 days and Priority Mail at 2 to 3 days, so a local letter can arrive as fast as Priority Mail. Priority Mail is more predictable over long distances, and it includes tracking and insurance, which First-Class Mail doesn’t offer without extra services.

Can you track First-Class Mail?

Only with an extra service. A standard First-Class Mail letter has no tracking, but adding Certified Mail or another delivery-confirmation service gives it a tracking number and proof of delivery. Priority Mail includes USPS Tracking at no extra charge on every shipment.

Sources

• USPS: First-Class Mail
• USPS: Priority Mail
• USPS: Ground Advantage
• USPS Newsroom: Introducing USPS Ground Advantage (July 10, 2023)

Part of our USPS Services guide. Related: Ground Advantage, USPS Priority Mail, Priority Mail Express.