Send a PDF Letter
What it is
PDF letter mode lets you upload any PDF document as a windowed or windowless 8.5×11 letter. thanks.io prints it, addresses it, envelopes it, and mails it. You never touch the envelope. Letters mail in a standard US business envelope (#10, 4.125″ × 9.5″).
This is the right tool for: newsletters, CMA reports, insurance policy summaries, multi-page proposals, and any document that lives naturally as a full-page formatted file.
When to use it
- Monthly newsletter to your book of business
- Automated CMA (Comparative Market Analysis) letter to a prospect
- Insurance policy renewal notice or summary
- Multi-page proposal or offer package
- Any content that already exists as a PDF and needs to be mailed
How to send a PDF letter
- Click Send Mail in the sidebar.
- On Choose What To Send, pick Windowed Letter or Windowless Letter.
- On How Would You Like To Send Your Letter?, click Upload Full PDF. For a windowed letter, confirm that page 1 leaves the address area blank by clicking I Understand, Continue.
- On Upload PDF, upload an 8.5 × 11 PDF of up to 12 pages and 30MB, or paste the address of a PDF you host under Or use a PDF you host. There is no Design step: your PDF is the whole letter.
- On Select Recipients, click Add Recipients and add your recipients (manually, from a CSV, from a mailing list, or with a radius search).
- On Review & Confirm, check the cost breakdown, including any Additional Pages line, and click Submit Order & Send Now.
See the Send Mail Walkthrough for every step.
To mail the same PDF again later, save it as a letter creative: in Creatives → New creative, choose a letter as the mail piece, then Upload Full PDF on the Writing step. Then click Send it on its card whenever you want to mail it.
Automating PDF letters
For API orders, pass the PDF link in the pdf_only_url parameter. In Zapier, map the PDF link to the PDF field in the thanks.io action. You can use a publicly accessible PDF URL or a Google Drive PDF sharing link.
Cost
The first physical page is included in the base per-piece price. Each additional physical page adds approximately $0.20 per piece. A physical page is one sheet of paper - a page printed front/back counts as one physical page, not two. For current pricing, see thanks.io/pricing.
Tips & best practices
- For windowed letters, leave the upper-left address area of page 1 blank. thanks.io prints the recipient's address there for you (see Limits & gotchas below).
- Add your phone number, email, and website to every page of the PDF - not just the first page. Recipients sometimes flip to the last page first.
- For newsletters, include one clear call-to-action on page 1. "Scan here to schedule a call" or include your direct phone number with a QR code.
- Use personalized salutations in the PDF if your tool supports it (e.g., Canva doesn't support variable fields; use ChatGPT to pre-generate personalized copies, or send a Handwritten Cover Letter with personalization fields and attach your PDF as additional pages).
- Test with a single piece to yourself before sending a full list.
Limits & gotchas
- PDF-only mode is available for both windowed and windowless letters.
- Windowed letters: don't put the recipient's address in your PDF. thanks.io prints each recipient's name and address in the upper-left area of page 1, where it shows through the envelope window. An address already in your PDF gets printed over, so the recipient ends up with two overlapping addresses. Leave that area of page 1 blank, on a white or light background. This applies to API and Zapier orders too: send the address in the recipient fields, not in the PDF.
- Windowless letters don't have this constraint. The address is printed on the envelope, so your PDF can use the full page.
- Each additional physical page costs $0.20 per piece. A sheet printed front/back is one physical page, not two. A 4-page PDF (2 sheets, front/back) = base price + $0.20 × 1 additional physical page.
- Duplicate Prevention applies (36-hour window), same as all other mailer types.