USPS First-Class Mail in 2026: Prices, Weight Limits, Delivery Times, and What Replaced First-Class Package

USPS First-Class Mail is the Postal Service's standard service for letters up to 3.5 oz and large envelopes (flats) up to 13 oz, delivered in 1 to 5 days. Since July 12, 2026, a 1 oz stamped letter costs 82 cents; packages no longer travel as First-Class at all, because USPS replaced First-Class Package Service with USPS Ground Advantage in July 2023.

That last point is where most older guides, including the earlier version of this one, go wrong. Below are the current prices, limits, and delivery times, and a clear rule for when an ecommerce brand should use First-Class Mail versus Ground Advantage or Priority Mail.

Updated October 22, 2026.

What is USPS First-Class Mail?

First-Class Mail is USPS's service for postcards, letters, and large envelopes. According to USPS, letters can weigh up to 3.5 oz and large envelopes up to 13 oz, and mail is delivered in 1 to 5 days. Mailpieces must meet USPS size and shape rules: letters that exceed standard length, height, or thickness are charged large-envelope prices, and flats that are rigid, uneven in thickness, or oversized are charged package prices and sent via Ground Advantage.

How much does First-Class Mail cost in 2026?

USPS raised mailing prices on July 12, 2026, an increase of about 4.8% across mailing services (USPS price filing announcement). Current single-piece prices:

USPS's First-Class Mail page also lists starting prices of $1.31 for square, oversized, or unusually shaped letters and $1.69 for large envelopes. Certified Mail, the most common add-on for proof of delivery, is $5.55 as of July 12, 2026, per Pitney Bowes' USPS rate summary.

Worked example: a 3 oz stamped invoice packet costs $0.82 for the first ounce plus 2 × $0.29 for the next two, or $1.40. The same mailing on a postage meter costs $0.78 + $0.58 = $1.36.

How long does First-Class Mail take?

USPS's standard for First-Class Mail is 1 to 5 days. When USPS revised its service standards in 2025, it said it was preserving the existing First-Class Mail day ranges and that standard delivery would not exceed five days (USPS Link). Local mail tends to arrive at the fast end of the range and cross-country mail at the slow end. USPS lets you check the expected delivery window by ZIP Code and mailing date on usps.com. For daily delivery cutoffs, see our guide to what time USPS stops delivering.

What happened to First-Class Package Service?

USPS launched USPS Ground Advantage on July 10, 2023, retiring First-Class Package Service, Parcel Select Ground, and Retail Ground (USPS newsroom). Today, anything that is a package rather than a letter or flat ships as Ground Advantage or Priority Mail. If a label tool, checkout plugin, or older guide still offers "First-Class Package," it is out of date. Our USPS Ground Advantage guide covers the replacement service in detail.

First-Class Mail vs Ground Advantage vs Priority Mail: which should you use?

Ground Advantage and Priority Mail figures are from USPS's Ground Advantage and Priority Mail pages; retail Post Office prices are higher than the commercial prices businesses pay through shipping software or a 3PL. Delivery times are estimates, not guarantees.

The simple rule: if it fits in an envelope and is flexible, use First-Class Mail. If it is a box, a rigid mailer, or anything you need to track by default, use Ground Advantage, and step up to Priority Mail only when the delivery promise requires it. To compare package options on cost, see our guide to the cheapest way to mail a package and our roundup of USPS shipping cost calculators.

Can you track First-Class Mail?

Not by default. USPS says business mail is trackable only with certain extra services. For documents where proof matters, such as contracts, notices, or chargeback evidence, add Certified Mail (proof of mailing and delivery) or a Certificate of Mailing (an official record of the mailing date). For anything valuable, ship it as a package with tracking and insurance included instead.

How do ecommerce brands use First-Class Mail?

For most online stores, First-Class Mail handles the paper side of the business rather than orders: invoices and statements for wholesale accounts, warranty cards, replacement inserts, gift cards in flat envelopes, and legal or compliance notices. Orders themselves, even small and light ones, ship as packages.

That is where a fulfillment partner matters. Atomix Logistics picks, packs, and ships ecommerce orders from fulfillment centers in Milwaukee, Wisconsin; Salt Lake City, Utah; and Baltimore, Maryland, choosing the service that meets each order's delivery promise, with every order double-scanned and its packout video-recorded. See our locations and fulfillment pricing.

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Frequently Asked Questions

How much is a First-Class stamp in 2026?

A First-Class Mail Forever stamp for a 1 oz letter costs 82 cents as of July 12, 2026, up from 78 cents. Each additional ounce is 29 cents, and a domestic postcard is 65 cents.

What is the weight limit for First-Class Mail?

Letters can weigh up to 3.5 oz and large envelopes (flats) up to 13 oz. Heavier, rigid, or oversized items are charged package prices and ship as USPS Ground Advantage or Priority Mail.

How long does First-Class Mail take to arrive?

USPS's service standard for First-Class Mail is 1 to 5 days. Local mail usually arrives faster and cross-country mail closer to the end of the range.

Can I still send a package by First-Class?

No. USPS retired First-Class Package Service when it launched USPS Ground Advantage on July 10, 2023. Small packages now ship as Ground Advantage, which includes tracking and $100 of insurance.

Does First-Class Mail include tracking?

Not by default. Tracking or proof of delivery requires an extra service such as Certified Mail. Packages sent with Ground Advantage or Priority Mail include tracking.

What is the difference between First-Class Mail and Priority Mail?

First-Class Mail is for letters and flat envelopes up to 13 oz, delivered in 1 to 5 days. Priority Mail is a package service for items up to 70 lb, delivered in an estimated 2 to 3 days with tracking and up to $100 of insurance on most shipments.