For nonprofits
Donor thank-you letters and tax receipts, sent as real mail
By Justin Winter · Updated August 22, 2026
For a nonprofit that wants a major donor's thank-you letter to actually arrive as physical mail, or an annual tax-receipt letter to go out to a manageable donor list, paperplane prints and mails each one through USPS — $1.99 First-Class per letter, or Certified Mail if a high-value gift acknowledgment needs proof of delivery. This is not a fundraising-campaign platform: there is no donor CRM, no appeal scheduling, and no mail-merge personalization beyond the name and address block.
Nonprofits mail donors for two very different reasons: a personal, high-touch thank-you to someone who gave significantly, and a once-a-year acknowledgment letter that has to reach everyone who gave that year. paperplane handles both as real USPS mail — but it is built around a manageable donor list you can see and check, not a mass fundraising campaign with thousands of varied appeals going out on a schedule.
Two ways to send, depending on the letter
A single major-donor thank-you goes through the regular send flow: write the letter, add the donor's name and address, pick First-Class or Certified, and it's printed and mailed. For an annual tax-receipt letter that needs to reach a whole donor list with the same wording, switch to bulk mode on the send page and upload a CSV or TSV export from whatever you track donors in — spreadsheet, donor database export, it doesn't matter. paperplane matches your columns (name, address, city, state, ZIP) automatically, shows you every row's status before anything sends, and creates one individually addressed First-Class letter per row once you confirm.
What the spreadsheet upload is, and isn't
Every donor in a batch receives identical letter text — that fits a general "thank you for your support this year" acknowledgment, but not a letter that states each donor's specific gift amount or a personalized paragraph per person. There's no bulk discount tier, no send scheduling, no reply envelopes or donation-card inserts, and no postcards. Each row becomes its own order, tracked individually, the same as a single letter placed by hand — there is no separate "campaign" record or response-rate dashboard layered on top.
| What you need | Fits paperplane today? |
|---|---|
| A personal thank-you letter to one major donor | Yes — send individually, First-Class or Certified. |
| A shared-text annual tax-receipt letter to 50–5,000 donors | Yes — one CSV upload, one letter per row. |
| A receipt letter that states each donor's own gift amount | No — every row in a batch gets the same text; send those individually. |
| A seasonal fundraising appeal with reply cards and response tracking | No — no inserts, no campaign analytics, no donation-card fulfillment. |
| Proof a high-value acknowledgment was sent and received | Yes — Certified Mail or Certified + electronic Return Receipt, sent individually. |
Pricing
| Service | Price | Best for |
|---|---|---|
| First-Class | $1.99 | Routine thank-yous and the annual tax-receipt batch. |
| Certified Mail | $12.99 | A major gift acknowledgment you want a mailing record for. |
| Certified + electronic Return Receipt | $14.99 | A major gift acknowledgment where you also want the donor's signed delivery confirmation. |
| Priority Mail | $24.99 | A time-sensitive acknowledgment that needs to arrive fast. |
There's no subscription or per-seat fee to use the spreadsheet upload — you pay the per-letter rate above whether it's one thank-you or a few hundred receipt letters. In sandbox mode you can run a whole donor list through for free to check formatting before a single real letter goes out.
A note on tax-receipt content
We handle the printing, mailing, and — if you choose it — Certified tracking and proof of delivery. What a written acknowledgment must say to satisfy IRS substantiation requirements for a given gift depends on the gift's size and structure, and this is general information about mailing options, not tax advice. Confirm your letter's required content with current IRS guidance or your organization's accountant before relying on it for donor tax documentation.
Related: for a batch mailing beyond donor receipts, see mailing a whole client list; for a gift acknowledgment that needs documented proof, see what Certified Mail is.
Common questions
Can I send my whole annual donor list at once, or only one letter at a time?
Both. For a single major-donor thank-you, send it individually — write the letter, add the recipient, choose First-Class or Certified, done. For an annual tax-receipt run to a larger list, use the spreadsheet upload on the send page: drop in a CSV or TSV of donor names and addresses, and paperplane creates one individually addressed letter per row. Every recipient in that batch gets identical letter text — there is no per-donor gift amount or personalized paragraph merged in today, so a batch works for a shared boilerplate ("thank you for your support this year") but not for a letter that states each donor's specific contribution amount.
Does a paperplane letter satisfy the IRS written-acknowledgment requirement for donations?
We can get your acknowledgment letter printed, mailed, and — if you choose Certified Mail — tracked and proof-of-delivered. What the letter itself needs to say to satisfy IRS substantiation rules for a given gift size (the $250 written-acknowledgment threshold, quid pro quo disclosures, and so on) is a compliance question specific to your organization and the gift. This is general information about mailing options, not tax or legal advice — check current IRS guidance or your accountant for what the letter's content must include.
Is this a replacement for a fundraising appeal or a mail campaign platform?
No, and we want to be upfront about that rather than let you find out mid-mailing. paperplane has no campaign scheduling, no A/B testing, no reply-device or donation-card inserts, no postcards, and no per-donor personalization beyond the address block. If you run seasonal appeals to thousands of donors with varied asks and tracked response rates, that is a job for a dedicated fundraising-mail vendor, not this. What works well here is a smaller, high-value use: personal thank-yous to major donors, and a shared-text annual receipt letter to a list you can review in a spreadsheet before it sends.
Should a major donor's thank-you go Certified instead of First-Class?
Most thank-you letters don't need it — First-Class at $1.99 is fine for routine acknowledgments. Certified Mail ($12.99) or Certified with electronic Return Receipt ($14.99) makes sense when the gift is large enough that your board or the donor themselves would want documented proof the letter was sent and received, or when the letter doubles as a formal tax acknowledgment for a gift you want a paper trail on.