What Is the Cheapest Way to Mail a Letter?
The cheapest correct option is usually the lowest-priced service that actually fits the completed mailpiece. Underpaying is not a saving; overpaying often starts with classifying the envelope incorrectly.
Classify Before You Price
For ordinary U.S. correspondence, first decide whether the finished piece qualifies as a machinable letter. Check destination, length, height, thickness, weight, flexibility, and whether the address can be read by automated equipment. A square, rigid, lumpy, or oversized piece may need a surcharge or a different mail category.
Lowest-Cost Decision Order
- Remove unnecessary inserts and use an envelope that stays within letter standards.
- Weigh the sealed piece, not its individual parts.
- Use ordinary First-Class Mail when its delivery and service level meet the need.
- Add only the postage required for weight and applicable surcharges.
- Add tracking, insurance, or signature service only when that extra service is available for the selected mail class and its protection is worth the added cost. Not every extra service can be attached to every letter or postage method.
Example
At rates effective July 12, 2026, a qualifying stamped letter up to one ounce starts at $0.82. A letter over one ounce adds $0.29 for each additional ounce step. If it is nonmachinable, a $0.49 surcharge can also apply. Those values illustrate why weighing and shaping the envelope can matter more than hunting for one extra stamp.
Once the finished letter postage is known, buy postage stamps by category, package quantity, current price, and availability.
Sources and Scope
Extra-service eligibility depends on the mail class and preparation; verify the completed piece.