Invoice Stamp - company seal and signature on invoice PDFs

Many businesses are required, or simply prefer, to show a company seal or a scanned signature on their invoices. Invoice Stamp does exactly that, and nothing else.

What it does

• Draws your stamp image on the last page only of every generated invoice PDF, never on intermediate pages.
• Places it in the footer area: left (under the payment terms), centre, or right (under the totals).
• Keeps the image aspect ratio automatically. You set the width; the height follows.
• Upload, preview and delete the image from the module setup page. No FTP, no file editing.

Collision-safe positioning

The invoice footer is a crowded area. The module measures the real layout of each invoice before drawing:

• It clears the totals table, whose height varies with the number of VAT lines.
• It clears the payments table when the invoice has payments recorded.
• It always stays above the free text and the footer legal mentions.
• If the position you chose has no room on a particular invoice, the stamp falls back to the free column at full size instead of shrinking into an illegible smear.

Fine tuning

Width and margins can be entered in millimetres or pixels, whichever you prefer. Pixels are converted at 96 dpi. Switching the unit rescales the values so the stamp keeps its physical size. Horizontal and vertical margins move the stamp in all four directions.

Upgrade safe

No core file is modified. The module uses the afterPDFTotalTable hook that the standard invoice PDF model already exposes, so a Dolibarr upgrade cannot overwrite the customisation. Your uploaded stamp is stored outside the module directory, per entity, so it survives module updates and reinstalls.

Requirements

• Dolibarr 23.0 or 24.0
• PHP 7.0 or later
• The Invoices module enabled
• The active invoice PDF model must be sponge (the Dolibarr default) or octopus

Please note

• The crabe PDF model does not expose the required hook, so the module has no effect with it.
• Applies to customer invoices only. Orders, proposals and supplier documents are not affected.
• No stamp image is included: you upload your own.
• Already generated PDFs are not modified. Regenerate an invoice to see the stamp on it.

Getting started

1. Install the module and enable it.
2. Open its setup page and upload your stamp, ideally a PNG with a transparent background around 600 px wide.
3. Pick a position and save. Regenerate an invoice.

Licence: GPL-3.0-or-later.