Remittance Envelopes: The Complete Guide for Nonprofits, Fundraisers and Reply Mail

A remittance envelope is not just a reply envelope. It is the device that converts a donor's intention to give into an actual gift received. Every friction point that stands between a donor reading your appeal and their check going in the mail reduces response rate and the remittance envelope is where most of that friction lives. A poorly designed remittance envelope asks donors to write in too-small spaces, does not tell them where to send it, and does not confirm what their gift will accomplish. A well-designed one makes donating feel obvious and easy.

This guide covers everything about remittance envelopes: the difference between the two formats (#6 3/4 vs #9), why the large flap is the defining feature of the true remittance format, exactly what to print on it and what to leave off, how to nest it correctly inside a #10 outgoing envelope, the postage-paid vs donor-pays-postage decision, and the year-end timing that makes October through December the highest-stakes season for every donation mailing program.

What Is a Remittance Envelope?

A remittance envelope is a small reply envelope, typically in #6 3/4 format (3-5/8 x 6-1/2 inches), with an oversized flap that folds over the face of the sealed envelope. That large flap carries a printed form the response device where the donor fills in their name, mailing address, gift amount, and payment method. When the donor seals the envelope with their check or credit card information inside, the flap folds down to cover the form, carrying the donor's information on the outside of the sealed piece.

This is the critical design logic of a remittance envelope: the response form and the mailing envelope are the same object. The donor does not need a separate reply card or payment form the envelope flap is the form. This eliminates one component from the mailing package, reduces the chance of a donor losing the reply card, and makes the response action as simple as possible: fill in the flap, enclose payment, seal, and mail.

Remittance Envelope (#6 3/4) vs Reply Envelope (#9): Which to Use

Format	Size	Flap	Has Printed Form?	Best For
#6 3/4 Remittance	3-5/8 x 6-1/2"	Extra-large, printed with donation form	Yes name, amount, credit card fields on flap	Nonprofit donation appeals, church offerings, pledge drives
#9 Reply	3-7/8 x 8-7/8"	Standard flap, no printed form	No blank return envelope	Billing reply, subscription renewal, document return
#6 3/4 Security Tinted	3-5/8 x 6-1/2"	Standard or large	Optional	Payment reply for financial or legal organizations

The #6 3/4 remittance format is specific to programs where the form and the envelope are the same piece. The #9 is a standard reply envelope that carries no form it is the right choice for billing return programs and any situation where the reply form is a separate insert rather than printed on the flap. For most nonprofit donation programs, the #6 3/4 remittance with the large printed flap is the correct choice.

How the #6 3/4 Remittance Envelope Nests in a #10 Outgoing

The standard direct mail donation package is a #10 outgoing envelope carrying three things: the appeal letter, the reply device, and the remittance envelope. In the true remittance format, the reply device is printed on the remittance envelope's flap so the package is reduced to two inserts: the letter and the remittance envelope.

A #6 3/4 envelope (3-5/8 x 6-1/2 inches) fits inside a #10 (4-1/8 x 9-1/2 inches) with approximately 1/2-inch clearance at height and 3 inches of remaining length, which accommodates a folded one- or two-page letter alongside it. The total assembled piece typically runs 0.5 to 0.7 ounces for a one-page letter, well within the single-stamp First-Class letter rate of $0.78.

Before any volume mailing, test the nesting: assemble a complete package with the letter folded as it will be in production and the remittance envelope inside the #10. The package must seal cleanly without forcing the flap, must not create a lump thicker than 1/4 inch (which triggers the nonmachinable $0.49 surcharge), and must weigh within the first-ounce bracket if you want single-stamp postage. Heavier paper or additional inserts push pieces toward the second-ounce bracket at $0.29 additional. Test the complete package before printing any quantity.

What to Print on the Remittance Envelope Flap

The flap is the response device. Every field you add creates friction. Every unclear field reduces completion rate. Keep it to the minimum that your program actually requires to process the gift:

Essential fields (always include): Donor name, mailing address (at minimum city, state, ZIP if you have existing donor records), gift amount options with checkboxes, and "Other: $____" for non-standard amounts. Your organization's pre-printed return address on the envelope face so the donor does not have to write it. A brief gift purpose line ("My gift will ______") helps donors feel connected to the impact.

Conditional fields: Credit card number, expiration, and security code if your program accepts card payments by mail. Email address for receipt delivery. "In memory of" or "In honor of" if your program tracks tribute gifts.

Skip: Long mission statements, extensive explanatory copy, more than four gift amount options, excessive donor history fields. Every additional field reduces completion rate. The remittance flap is not a survey it is a transaction device.

The Gift Amount Ladder: One of the Most Tested Variables in Fundraising

The suggested amounts printed on your remittance envelope flap directly influence the average gift size. The tested principle: the amounts you suggest anchor donor expectations. Donors who see a lowest option of $25 will cluster around $25. Donors who see $50 as the lowest option will cluster higher. For house list donor mailings (existing donors), your ask amounts should be anchored to each donor's giving history ideally the last gift amount as the starting option, with one option below and two above.

According to the 2025 ANA/DMA Response Rate benchmarks, nonprofit house list donor appeals achieve 5% to 9% response rates on properly structured campaigns, while cold acquisition mailings average 0.5% to 1.5%. A P.S. line in the appeal letter that reinforces the ask has been shown to boost response by approximately 13% (Gitnux research compiled from direct mail testing). Postage-paid return envelopes consistently outperform donor-pays-postage formats eliminating the friction of finding a stamp at the moment of giving has a measurable positive impact on response rates.

Postage-Paid vs Donor Pays: The Economics

A Business Reply Mail (BRM) permit allows you to provide postage-paid return envelopes. Donors pay nothing to mail their gift. You pay the postage only on envelopes that are actually returned (typically $0.75 to $1.20 per returned piece depending on permit class and mail volume).

The alternative is printing a "first-class postage required" or "please affix stamp" note on the return envelope flap. This is free at the production stage. The trade-off is a measurable reduction in response rate donors who would have mailed immediately sometimes do not because they do not have a stamp handy, and that moment of friction turns into a "I'll do it later" that never happens.

For small-volume nonprofit programs without a BRM permit, the postage savings from asking donors to stamp their replies often does not offset the response rate reduction. For large-volume programs where BRM postage cost is known and trackable, the decision can be modeled on your actual per-piece economics.

Year-End Giving Season: October Through December

Approximately 20% of annual charitable donations arrive in October through December, driven by tax deadline awareness, matching gift programs, and year-end generosity. This is the most competitive period in the mailbox for any nonprofit mailing program. Your remittance envelope and outgoing package must earn the open before anything else happens.

The outer envelope is the first decision point. A blank white #10 with a standard return address disappears in a competitive mail pile. A colored or starburst outer envelope creates visual distinction. A non-standard format (a 6x9 outer rather than a #10, for example) stands out simply by not being the expected shape. Handwritten-style fonts or a live stamp on the outer envelope (rather than a meter impression or indicia) signal personal correspondence rather than bulk mail, which consistently outperforms standard-appearance outer envelopes in direct mail testing.

Browse our colored and starburst outgoing envelope options at colored envelopes. For the #6 3/4 remittance format and #9 reply format, custom printing with your organization's name, return address, and logo is available through custom printed envelopes.

The Complete Year-End Donation Appeal Package

The most consistently effective structure for nonprofit direct mail, per decades of testing in the sector:

Outer envelope (#10 or 6x9, colored or starburst): Colored stock with teaser copy, or a non-standard format. Live stamp or handwritten-style address. Organization return address in upper left.

Appeal letter (one to four pages): Personal salutation. Story-driven opening. Specific ask amount anchored to donor history. Multiple asks within the letter. Strong P.S. reiterating the key ask.

Remittance envelope (#6 3/4 custom printed): Organization name and return address on face. Large flap with gift amount checkboxes, name/address fields, payment method options. Pre-affixed BRM postage or "please affix stamp" instruction.

This two-insert package (letter plus remittance envelope) is the baseline structure. Adding a lift note, photo card, or mission statement insert can improve response but also increases cost and assembly complexity. Test before scaling.

Why Choose Business Envelopes for Remittance and Reply Envelopes

Business Envelopes has supplied #6 3/4 remittance and #9 reply envelopes to US nonprofits, churches, membership organizations, and professional associations since 1997. Our #6 3/4 remittance envelope is available blank or custom printed with your organization's name, return address, and logo PDF proof before production, artwork on file for reorders. Available in plain white wove for custom printing and in colored wove and starburst formats to match your outgoing envelope. No minimums. Free ground shipping on every order. Printed orders ship in 7 to 10 business days from proof approval.

For the complete appeal mailing package, browse colored envelopes for the outgoing outer, #10 envelopes for standard outgoing formats, window envelopes for programs using mail-merge addressing, and self seal envelopes for outgoing formats where moisture-free sealing matters. See the complete catalog at all items.

Frequently Asked Questions

What is a remittance envelope?

A remittance envelope is a small reply envelope (typically #6 3/4, measuring 3-5/8 x 6-1/2 inches) with an oversized flap that serves as the printed donation form. The flap carries fields for donor name, address, gift amount, and payment method. When sealed, the flap covers and protects the enclosed payment. It is the standard reply device for nonprofit donation appeals, church offerings, and pledge programs.

What is the size of a remittance envelope?

The standard remittance envelope is #6 3/4, measuring 3-5/8 x 6-1/2 inches (92 x 165 mm). This size is specifically designed to nest inside a standard #10 outgoing envelope (4-1/8 x 9-1/2 inches) alongside a folded appeal letter, with the package typically weighing under 1 ounce for First-Class letter rate mailing.

What is the difference between a remittance envelope and a reply envelope?

A remittance envelope (#6 3/4) has an oversized flap with a printed response form the flap is the donation device. A reply envelope (#9) is a standard-size reply envelope without a printed form it is used when the response form is a separate insert. For donation programs, the remittance format reduces the package to two pieces (letter and envelope) rather than three (letter, reply card, and envelope).

How does a remittance envelope nest inside a #10?

A #6 3/4 envelope (3-5/8 x 6-1/2 inches) fits inside a #10 (4-1/8 x 9-1/2 inches) with approximately 1/2-inch height clearance and 3 inches of remaining length. A folded one-page letter fits alongside it. The assembled package typically weighs under 1 ounce, qualifying for single First-Class stamp ($0.78). Always test with a fully assembled piece before any volume run.

Should I use postage-paid (BRM) return envelopes or ask donors to stamp?

Postage-paid Business Reply Mail envelopes consistently outperform donor-stamps-required formats in response rate testing, because the friction of finding a stamp causes some donors who intended to give to delay and never follow through. For small programs without a BRM permit, the postage savings from asking donors to stamp often does not offset the response rate reduction. For large programs, model the per-piece economics on your actual return rate.

What should I print on the remittance envelope flap?

Essential: donor name field, mailing address, gift amount options with checkboxes (3 to 4 options) plus "Other: $____", brief gift purpose line. Conditional: credit card fields if you accept card by mail, email for receipt, tribute gift option. Skip: long copy, excessive survey fields. Every additional field reduces completion rate. The flap is a transaction device, not a survey.

Can I get remittance envelopes custom printed with my organization's logo?

Yes. Business Envelopes offers custom printing on #6 3/4 remittance envelopes with your organization name, return address, and logo. PDF proof before production, artwork stored on file for reorders. No minimums. Ships in 7 to 10 business days from proof approval. Available in white wove, colored wove, and starburst formats.