This page gives you a USPS-centered checklist to verify dimensions, weight, shape, and current postage before you drop your wedding invitations in the mail.
The short answer
To figure out wedding invitation postage, first weigh a fully assembled invitation suite on a postal scale. Then measure its thickness and check whether the envelope is rigid or flexible. Compare those numbers against USPS rules for letters, flats, and parcels so you buy the correct stamp. Finally, visit the USPS website to confirm current rates because they can change.
The decisions this settles
This page gives you a USPS-centered checklist to verify dimensions, weight, shape, and current postage before you drop your wedding invitations in the mail.
Questions to answer before you commit
- Does your fully assembled invitation fit through a standard USPS mail slot without bending?
- Is the thickness of your invitation envelope less than the letter limit or does it require nonmachinable surcharge?
- Will you use a forever stamp, a specific-value stamp, or do you need extra postage?
- Are you adding any enclosures (RSVP card, reception card, map) that change the weight or shape?
- Do you need to confirm the mailing date falls within a valid shipping window for your chosen service (e.g., first-class vs. priority)?
What each choice changes
| What to compare | What to ask for | The decision it changes |
|---|---|---|
| Envelope shape and size | Measure length, width, and thickness of the sealed envelope. Compare against USPS letter dimensions (max 6.125 x 11.5 x 0.25 in) vs. flat (max 12 x 15 x 0.75 in). | Determines whether you pay letter rate or flat rate, which affects number of stamps needed. |
| Weight per invitation suite | Weigh the completed envelope on a postal scale to nearest ounce. Check if it exceeds the standard 1-oz letter limit. | Additional ounces require extra postage. If weight exceeds 3.5 oz for letters, you must use a flat rate or parcel rate. |
| Paper stock and envelope rigidity | Test if the envelope can be bent easily or stands rigid. Hold it by one edge and see if it droops. | Rigid, nonbendable envelopes are nonmachinable and may incur a surcharge or need hand-canceling. |
| Return address placement | Verify the return address is in the correct location (upper-left corner) and printed/printed label with correct orientation. | Improper placement can cause delays or return to sender. May affect whether machine processing works. |
| Envelope closure method | Check if the envelope flap is moistened, taped, or uses a peel-and-seal strip. Ensure no exposed adhesive or loose edges. | Loose flaps or exposed adhesive can catch in sorting machines, leading to damage or extra charges. |
| Postage verification method | Decide whether to use a postage meter, online postage, or stamps. For stamps, consider forever stamps vs. specific denomination stamps. | Forever stamps cover current 1-oz letter rate regardless of future increases, but extra ounces still need additional stamps. |
A worked example you can copy
Turning a guest list into a mailing count
- 72 households or couples invited together receive one invitation each.
- 14 people need their own mailing: adult children at other addresses, colleagues, single friends invited alone.
- That is 86 invitations to send.
- Add 8 spares for addressing mistakes, keepsakes and late additions.
- Order 94. Note that this is a mailing count, not a guest count.
| Line | Amount |
|---|---|
| Households | 72 |
| Separate mailings | 14 |
| Base invitations | 86 |
| Spares | 8 |
| Order quantity | 94 |
Where this usually goes wrong
None of these are exotic. They are the ordinary ways this decision goes wrong, and each one is caught by asking a single extra question.
Watch for
- Assuming all invitations weigh the same: adding a heavy cardstock RSVP card or extra insert can push weight over the 1-oz limit, requiring extra postage for every single envelope.
- Using a forever stamp on a nonmachinable envelope: a thick or rigid envelope may need a nonmachinable surcharge that a forever stamp alone doesn’t cover, causing the invitation to be returned.
- Not accounting for envelope shape: square envelopes are treated as flats or parcels even if light, so you pay a higher rate than for a standard rectangular letter.
Your next conversation, in checklist form
Your next conversation, in checklist form
- Weigh the fully assembled invitation suite on a postal scale.
- Measure the envelope’s length, width, and thickness against USPS letter limits.
- Check that the envelope is flexible enough to pass through a slot without damage.
- Print or write the return address clearly in the correct position.
- Apply the correct postage based on weight, shape, and any nonmachinable features.
- Take one completed invitation to the post office for a manual postage check before mailing the full batch.
Questions couples ask
Can I use a forever stamp for my wedding invitation?
Yes, a forever stamp covers the current 1-ounce letter rate, but if your invitation weighs more than 1 ounce, you need additional postage. Also check that your envelope meets the letter shape and size requirements, or you may need a different stamp.
Do I need to hand-cancel my wedding invitations?
Hand-canceling is optional and mainly protects envelopes with wax seals, ribbons, or heavy embellishments. It costs extra and delays delivery, so only request it if your invitations are truly nonmachinable.
How do I know if my invitation needs extra postage?
Weigh your fully assembled invitation on a postal scale. If it exceeds 1 ounce, you need additional ounces of postage. Also, if the envelope is thicker than 0.25 inch, rigid, or square, it may require nonmachinable surcharge or a flat rate—verify with USPS guidelines.
Your next decision
Now that your postage is sorted, learn how to address your invitation envelopes properly with our guide to wedding invitation addressing.
