The Complete Wedding Postage & Envelope Mailing Guide
Everything you need to know about USPS non-machinable surcharges, vintage stamps, and mailing timelines.
1. Understanding the USPS Non-Machinable Surcharge ($0.44)
USPS sorting facilities use high-speed automated sorting machines that bend letters around tight conveyor rollers at 30,000 envelopes per hour. An envelope is legally deemed non-machinable if it:
- Has an aspect ratio (length divided by height) of less than 1.3 or more than 2.5 (e.g. square envelopes).
- Contains rigid items like acrylic, wooden invites, keys, or stiff cardboard inserts.
- Has an uneven thickness greater than 1/4 inch caused by wax seals or ribbon knots.
- Has addresses printed parallel to the shorter edge of the envelope.
2. How to Use Vintage Postage Stamps Legally
Unused vintage US postage stamps issued after 1861 remain legal tender at their face value. If your suite requires $1.17 in postage, you can curate a combination of vintage 15¢, 22¢, and 33¢ stamps as long as the sum of their face values equals or exceeds $1.17.
Frequently Asked Questions
Do RSVP envelopes need their own stamps?
Yes. Proper wedding etiquette requires the host to pre-address and affix a 1-oz Forever stamp ($0.73) or Postcard stamp ($0.56) to every RSVP return envelope.
What happens if an invitation has insufficient postage?
USPS will return the envelope to your return address with a yellow 'Returned for Postage' sticker, or attempt to deliver it to your guest with a 'Postage Due' fee.
When should wedding invitations be mailed?
Mail domestic invitations 6 to 8 weeks before the wedding (8 to 12 weeks for destination weddings).