Custom signatures

Upload a scan of your signature once. Paperjoy traces it into pen strokes, and the robot signs your postcards with it.

A postcard with a short message and a real, flowing handwritten signature underlined in the bottom left corner.

Plans

Plan	Custom signatures
Start	—
Pro	1
Business	Up to 3

Compare plans in Billing. If you move to a plan with fewer signatures, the extra ones can’t be used on new postcards.

Add a signature

Scan your signature

Sign in dark ink on plain white paper and take a sharp, well-lit photo or scan. Crop it close to the signature. JPG, PNG, and WebP files up to 5 MB work.

Upload it

Open Ustawienia → Podpisy (Settings → Signatures). Enter a name, such as your own, choose the file, and click Prześlij podpis (Upload signature).

Wait for activation

We trace the signature by hand. It is ready within 3 business days, and we email you when it’s active.

Scans can only be uploaded in the app. The API lists, retrieves, and deletes signatures, but doesn’t accept files.

The Signatures settings page with the upload form and an active signature named Marta Nowak.

Use it

Editor
API
MCP

Under Podpis (Signature), open the Własny podpis (Custom signature) tab and pick your signature.

Find the signature ID:

curl https://paperjoy.co/api/signatures \
  --header "Authorization: Bearer $PAPERJOY_API_KEY" \
  --header "Accept: application/json"

{
  "data": [
    {
      "id": "sig_ZeXOkSQjTp",
      "name": "Marta Nowak",
      "status": "active",
      "created_at": "2026-10-10T09:00:00+00:00",
      "updated_at": "2026-10-12T11:20:00+00:00"
    }
  ]
}

Then send signature_id instead of signature when you create or preview a postcard:

{
  "content": "Thank you for being with us for a whole year!",
  "signature_id": "sig_ZeXOkSQjTp",
  "font_id": "font-1"
}

Only signatures with "status": "active" can be used. A signature that is still in_progress, deleted, or not included in your plan returns a 422 error on signature_id.

Ask your assistant to use your signature. It calls list-signatures-tool to find the ID and passes it to create-postcard-tool.

Delete a signature

Click the trash icon next to the signature in the app, or call DELETE /api/signatures/{id}. The signature disappears from the list right away and can’t be used on new postcards. Postcards that are already ordered are still signed with it. Paperjoy permanently deletes the signature and its files after 30 days.

Get started

Ways to send

Postcards

Account

API reference

Custom signatures

Plans

Add a signature

Use it

Delete a signature

​Plans

​Add a signature

​Use it

​Delete a signature

Plans

Add a signature

Use it

Delete a signature