Forever Stamps: Complete Guide to Costs Rates and Usage

You’re new to mailing. Maybe you’ve never bought a stamp in your life. That’s okay. By the end of this guide, you’ll know exactly which stamp to use, how many to apply, where to put it, and what to do when your envelope is heavier, square, or going overseas. We’ll keep it simple, practical, and a little conversational—because postage should not feel like decoding a puzzle.

Quick reality check: the Forever Stamp covers a 1 oz First‑Class letter and is currently 78¢ (and stable until at least July 2026). Postcards are 61¢. Additional ounce is 28¢. There are dedicated 2‑oz ($1.07) and 3‑oz ($1.36) stamps, a 1 oz non‑machinable ($1.27) stamp for tricky shapes, and a Global Forever stamp for 1 oz international letters at $1.65. Breathe—we’ll walk through it step by step.

First things first: what a Forever Stamp does and doesn’t do

• A Forever Stamp = 1 oz First‑Class letter postage.
• It never expires. If the price changes in the future, your stamps still count for the current 1 oz rate.
• Use Forever Stamps for letters in standard sizes. For heavier letters, add either an “additional ounce” stamp (28¢) or use the dedicated 2‑oz / 3‑oz stamps.
• For postcards, use the postcard stamp (61¢). Forever isn’t for postcard pricing.
• For international 1 oz letters, use a Global Forever (1.65). It’s an easy one‑and‑done.

If you’re thinking, “Can I paste a bunch of Forever Stamps to pay for Priority Mail?” Technically yes—but it’s clunky and not recommended for business mail. Use a printed label for Priority or Express. It’s faster and professional.

The stamp math: updated rates you actually need

Here’s your quick reference for 2025–2026:

Tip: Dedicated 2‑oz and 3‑oz stamps keep you from doing math or mixing denominations. If you mail a lot of multi‑page letters (invoices, statements), they are a time‑saver.

Envelope sizes and shapes: the rules that really matter

USPS pricing depends on whether your envelope is “machinable.” If it slides through sorting machines smoothly, you pay the normal price. If it’s odd—square, too rigid, has clasps or strings—it’s non‑machinable and costs more.

• Standard letter (machinable):
  • Height: 3.5″–6.125″
  • Length: 5″–11.5″
  • Thickness: 0.007″–0.25″
  • Rectangular, flexible, no bumps
• Non‑machinable letter (1 oz): Use the $1.27 stamp when:
  • Square shape (e.g., 6″ × 6″ invites)
  • Rigid or with clasps/buttons
  • Uneven thickness (lumpy)
• Large envelope (flat):
  • Typically up to 12″ × 15″
  • Thickness up to ~0.75″
  • Priced higher than letters; consider flats pricing rather than letter stamps

If your item is thicker than ~0.75″ or oddly shaped, it becomes a “package.” At that point, you’re in package/Priority pricing, not letter or flat rates.

How to mail a simple letter: beginner walk‑through

1. Write the address clearly.
   • Recipient address centered.
   • Return address in the top‑left corner.
   • Use black or blue ink, block letters are safest.
2. Weigh it.
   • If you don’t have a scale, estimate: a sheet of standard printer paper is about 0.16 oz. Four sheets plus the envelope often lands near 1 oz. More than that? Assume 2 oz or 3 oz and choose the matching stamp.
   • When in doubt, ask the post office counter to weigh it. They don’t bite.
3. Check the size/shape.
   • Rectangular and flexible? Great—machinable.
   • Square, rigid, or lumpy? Use the non‑machinable stamp at $1.27 for 1 oz.
4. Choose your stamp(s).
   • 1 oz letter: 1 Forever (78¢).
   • 2 oz letter: 1 Two‑Ounce ($1.07) or 1 Forever + 1 Additional Ounce (28¢).
   • 3 oz letter: 1 Three‑Ounce ($1.36) or 1 Forever + 2 × Additional Ounce (28¢ × 2).
   • Square 1 oz invite: 1 Non‑Machinable ($1.27).
5. Place the stamp at top‑right.
   • Clean, flat, not overlapping the edge.
   • Don’t plaster multiple stamps randomly—line them neatly if you’re mixing denominations.
6. Drop it in a mailbox or at the post office.
   • If you’re unsure, hand it to the clerk. Quick glance, peace of mind.

Postcards: tiny joy, different price

• Standard postcard stamp is 61¢.
• Size matters. Typical postcard dimensions are about 4″ × 6″. Oversized or oddly shaped cards may price as flats or non‑machinable. Keep it standard and you’ll be fine.
• Address and message on the same side; stamp in the top‑right corner.

If you love sending holiday postcards, this is the budget‑friendly way to share cheer without stuffing envelopes.

International letters: Global Forever makes it easy

• Use 1 Global Forever stamp ($1.65) for a 1 oz letter to most countries.
• Keep the envelope rectangular and machinable—international sorting still prefers clean shapes.
• If you’re sending more than 1 oz internationally, stop guessing. Have it weighed, then buy a printed label to avoid mis‑postage. It saves time, and sanity.

Priority Mail and Express: don’t use stamps, use labels

Yes, you could calculate the price and stick a mountain of stamps. But:

• It looks unprofessional, especially for business shipments.
• It’s time‑consuming and can cause processing delays.
• You lose tracking and automated address validation benefits.

Buy a printed label online or at the counter for Priority Mail or Express. You’ll get tracking, cleaner handling, and usually better overall outcomes.

Choosing designs: occasion matters more than we admit

Stamps send a tiny signal. It’s subtle, but real. Choose the vibe.

• Flag stamps 🇺🇸
  • Business mail, formal notices, invoices, government documents.
  • Professional, patriotic, straightforward.
• Flowers 🌸
  • Weddings, sympathy, thank‑yous, personal notes.
  • Soft, friendly, thoughtful.
• Santa and holiday designs 🎅
  • December cards, family newsletters, seasonal promotions.
  • Warm, festive, inviting.
• Special editions (Black Heritage, Lunar New Year, art series)
  • Event invites, cultural celebrations, anything you want remembered.
  • Adds personality and meaning.

Sometimes the stamp design says: “I cared.”

Real‑world examples: solve common scenarios fast

• Mailing a three‑page invoice (with envelope) to a client:
  • Likely 1–2 oz. If 2 oz, use 1 Two‑Ounce ($1.07). If unsure, add an “additional ounce” (28¢) to 1 Forever.
• Sending square wedding invitations:
  • 1 oz square is non‑machinable → use the $1.27 non‑machinable stamp.
• Holiday postcards to your customer list:
  • Use the postcard stamp (61¢); consider seasonal designs.
• International thank‑you letter (lightweight):
  • 1 Global Forever at $1.65.
• Bulk statements or catalogs (not packages):
  • Likely flat rates, not letters. Talk to the post office or your mailing provider, and consider presort options.

If it feels confusing, it’s okay. Mail rules are a little fussy; that’s how machines sort millions of pieces quickly.

Where to buy (and what to avoid)

• Buy from USPS.com, post offices, or authorized retailers: Forever Stamp Store and The USPS Stamps.
• Avoid 50%‑off “discount stamps” on general marketplaces (e.g., Shein, Temu). These catchy offers are, well, bad ideas for business or personal mail. They cause returned items, delays, and headaches.
• If you mail frequently, consider keeping a small kit: Forever stamps, additional ounce stamps, a few two‑ounce/three‑ounce stamps, and a Global Forever sheet. It save times and reduce mistakes.

Frequently made mistakes (and easy fixes)

• Using only 1 Forever Stamp for a 2 oz letter.
  • Fix: add 1 Additional Ounce (28¢) or swap to the $1.07 two‑ounce stamp.
• Ignoring shapes.
  • Square = non‑machinable. Use the $1.27 stamp for 1 oz squares; add ounces if heavier.
• Stamping Priority Mail.
  • It “work,” but don’t. Use a label, get tracking.
• Messy stamp placement.
  • Keep stamps neat, top‑right. Don’t cover the address area or barcode zones.

A simple decision tree (for beginners)

1. Is your envelope rectangular, flexible, and under 0.25″ thick?
   • Yes → It’s a letter. Weigh it.
   • No → It’s non‑machinable or a flat/package. Adjust accordingly.
2. Letter weight:
   • 1 oz → 1 Forever (78¢).
   • 2 oz → $1.07 two‑ounce stamp, or 1 Forever + 28¢.
   • 3 oz → $1.36 three‑ounce, or 1 Forever + 2 × 28¢.
3. Shape:
   • Square or rigid at 1 oz → $1.27 non‑machinable stamp.
   • If heavier, add ounces on top of non‑machinable pricing.
4. Destination:
   • U.S. postcard → 61¢ postcard stamp.
   • International 1 oz letter → 1.65 Global Forever.
   • Packages/Priority/Express → buy a printed label.

If you can follow those four steps, you basically win the mailing game.

Tiny human moment: why this still matters

I’ve seen new business owners freeze over a stamp sheet. It sounds silly until it’s you. “Is this enough? Will it be returned? Am I overpaying?” Then you learn the rules, and the anxiety fades.

One owner told me, quietly: “I stuck the stamp, pressed the envelope flat, and felt… calm.” Small thing. Big feeling. Mail still carries that.

Quick reference tables

Letters and special cases

Sizes

Our Forever Stamps information comes from:

Margaret Collins

Former USPS clerk with 25 years of service, now retired in Florida. She writes about Forever Stamps for the website, offering reliable insights on postal changes, discount opportunities, and practical mailing solutions for households.