Yes, Butterfly stamps labeled “NON-MACHINEABLE SURCHARGE” have permanent rate-based value, but they are not ordinary one-ounce Forever stamps. They follow the price of a one-ounce First-Class Mail letter that requires the nonmachinable surcharge. That value is $1.31 as of September 1, 2026: the $0.82 one-ounce letter price plus the $0.49 surcharge.
What a Butterfly stamp pays for
A current Nonmachinable Surcharge Butterfly stamp is intended for an eligible domestic First-Class Mail letter weighing no more than one ounce when the letter has a nonmachinable characteristic. The stamp covers both the basic one-ounce letter postage and the surcharge at the current rate.
The words on the stamp matter more than the butterfly artwork. USPS has issued different butterfly designs over time, but the “NON-MACHINEABLE SURCHARGE” wording identifies the rate category.
When an envelope may need the nonmachinable surcharge
- It is square rather than rectangular.
- It is rigid or does not bend easily.
- Its thickness is uneven or it contains a lumpy object.
- It has clasps, buttons, strings, ribbons or similar closures.
- Its address is parallel to the shorter dimension.
- It falls outside another USPS machinability standard.
A greeting-card envelope printed with a butterfly silhouette is a common signal that additional postage may be needed. The finished envelope—not the card package alone—determines the actual classification.
Butterfly stamp versus an ordinary Forever stamp
| Feature | Butterfly / Nonmachinable stamp | Ordinary Forever stamp |
|---|---|---|
| Rate category | One-ounce letter price plus nonmachinable surcharge | One-ounce machinable letter price |
| Current value | $1.31 | $0.82 |
| Typical use | Eligible square, rigid or otherwise nonmachinable domestic letter | Eligible standard domestic letter |
| Rate changes | Follows its named nonmachinable category | Follows the ordinary one-ounce letter category |
| Interchangeable one-for-one? | No | No |
Do older Butterfly stamps keep their value?
A genuine unused nondenominated Butterfly stamp identified for the Nonmachinable Surcharge rate continues to represent that current category, even when it was bought at a lower price. Check the exact wording and issue because butterfly artwork can also appear on fixed-denomination stamps or on stamps from another rate category.
When one Butterfly stamp is not enough
- Over one ounce: additional postage is required.
- Large envelope or parcel classification: the Butterfly stamp does not force the item to remain a letter.
- International destination: domestic nonmachinable-letter pricing is not an international rate.
- Extra services: tracking, insurance, certified mail or other services require their applicable fees.
For an unusual envelope, first determine its mail class, weight and dimensions. Use the postage decision guide, and see the specific rules for Forever stamps on square envelopes.
Frequently asked questions
Are Butterfly stamps the same as Forever stamps?
They share permanent rate-based behavior, but they represent different categories. A Butterfly stamp covers the one-ounce nonmachinable-letter price; an ordinary Forever stamp covers the standard one-ounce letter price.
Can I use a Butterfly stamp on a normal envelope?
It contributes its full postage value, but it may overpay a standard machinable letter. Match the stamp to the finished envelope rather than choosing it only for the design.
Can I use ordinary Forever stamps instead?
Yes. See the exact Butterfly-to-Forever stamp conversion, including the current shortfall and overpayment. Confirm the exact total for the finished mailpiece.
Does every stamp with a butterfly image have nonmachinable value?
No. Read the wording and identify the issue. The picture alone does not establish its denomination or rate category.
Rates and rules checked September 1, 2026: USPS Notice 123; USPS Eastern Tailed-Blue Butterfly announcement; USPS Eastern Tiger Swallowtail announcement. Rates and mailing standards can change.