Bates Numbering: What It Is and How to Add It to a PDF Free

By Michael Peters · Published August 21, 2026 · 7 min read

What Bates numbering is

Bates numbering (also called Bates stamping) places a unique, sequential identifier on every page of a document or document set — typically in a margin corner, in the form prefix + fixed-width number + optional suffix:

SMITH-000123   ACME-004501-CONFIDENTIAL   MED-000087

Once stamped, every page in a production can be cited unambiguously — “see SMITH-000123” identifies exactly one page, forever, regardless of how the file is later split, merged, or printed. That permanence is the whole point: page 14 of a PDF stops being page 14 the moment someone inserts a cover sheet, but a Bates number never moves.

The name comes from the Bates Automatic Numbering-Machine, a hand stamp patented in the 1890s by the Bates Manufacturing Company of New York. Its counter advanced automatically after each impression, so a clerk could stamp consecutive numbers across thousands of paper pages. The mechanical stamp is a museum piece now, but the name survived the transition to electronic documents intact.

Who requires it — and why

• Litigation discovery. The core use. Documents produced to the other side must be identifiable page by page; protective orders and discovery agreements routinely specify Bates-numbered productions, and deposition exhibits and court filings then cite those numbers. No statute mandates the practice by name, but in litigation it is a de facto requirement.
• Medical records. Records departments and medico-legal reviewers use Bates numbers to keep chart productions complete and citable — a gap in the sequence is immediate evidence of a missing page.
• Regulatory and compliance submissions. Audit responses, investigation files, and agency submissions often need page-level identifiers so correspondence can reference exact pages across agencies and years.
• Any large document set that gets cited. Contracts with schedules, due-diligence data rooms, insurance claim files — anywhere “which page, in which file?” must have one answer.

Anatomy of a Bates number

A well-formed Bates number has three parts, and each carries meaning:

• Prefix — identifies the producing party, matter, or custodian: SMITH-, ACME-, JONES2026-. In multi-party litigation the prefix is what stops two parties' page 000123 colliding.
• Number — sequential and zero-padded to a fixed width, usually six digits. Fixed width keeps numbers sorting correctly in filenames and load files (000123 sorts before 001000; unpadded 123 sorts after 1000).
• Suffix (optional) — commonly a confidentiality designation from the protective order: -CONFIDENTIAL, -ATTORNEYS-EYES-ONLY.

Convention places the stamp in the bottom-right corner of each page, though the only real rules are: outside the document's own content, identical position on every page, and readable at print size.

How to add Bates numbers to a PDF free, in the browser

The Bates Numbering tool on the free Mapsoft PDF Hub stamps a PDF in a couple of minutes, with nothing to install:

1. Open mapsoft.com/tools/Pdf/BatesNumbering and upload the PDF (drag-and-drop, file picker, or straight from cloud storage).
2. Set the prefix, number of digits, starting number, and optional suffix — e.g. prefix ABC- with 6 digits starting at 1 produces ABC-000001, ABC-000002, …
3. Choose header or footer placement, left, centre or right alignment, and the font size. A starting page option lets you leave a cover page unstamped, and facing pages mirrors the left/right position for double-sided printing.
4. Apply and download the stamped PDF.

The stamp is added to the page margins as new page content — the document's own text is untouched. Files are processed on our UK servers and deleted automatically afterwards; even so, standard practice applies: stamp the production copy, keep the unstamped original.

Keeping the sequence continuous across many files

Productions are rarely one PDF. Three ways to keep one unbroken sequence:

• Merge first, stamp once. Merge the PDFs into one file in production order, then Bates-number the merged file. Simplest when the set is modest and a single output file is acceptable — see our guide to merging PDFs.
• Chain the starting number. The online tool stamps one PDF at a time, so to keep separate files, note where each file ends and set the next file's starting number to continue the sequence: if document one ends at ABC-000214, start document two at 215.
• Batch tools for volume. Adobe Acrobat Pro's Bates feature stamps across multiple files in one pass (it is Pro-only — Acrobat Standard does not include it). On the desktop, Mapsoft's Impress Pro Acrobat plugin stamps Bates numbers, page numbers, dates and other text across whole folders of PDFs with full control over font, position, and formatting.

Best practices that save pain later

• Redact first, stamp last. Bates numbering should be the final step before production — after redaction is complete and the page set is final. Renumbering a production because a page was removed afterwards is exactly the mess the system exists to prevent.
• Pad generously. Six digits covers 999,999 pages; running out mid-production and switching width breaks sorting everywhere. Digits are cheap — width changes are not.
• Never re-use a range. Keep a simple production log — date, files, Bates range (e.g. ABC-000001–ABC-002144) — and always continue from the highest number ever issued for that prefix, even across productions months apart.
• One prefix per producing party or matter. Resist clever multi-part prefixes; the prefix only needs to make the range unique and attributable.
• Check the corners before stamping. If the document already has content in the stamp position (page numbers, footers of a scanned exhibit), switch to the header or the opposite corner rather than overprinting.

Bates numbers vs page numbers vs page labels

Three different things that look similar:

• Page numbers restart with every document and move when pages are inserted — fine for reading, useless for citation across a document set. See adding page numbers to PDFs.
• Page labels are metadata that changes what a PDF viewer displays in its page field (i, ii, iii, then 1, 2, 3) without stamping anything visible on the page — covered in our page labels guide.
• Bates numbers are stamped into the page content itself, unique across the entire set, and never reset. They survive printing, splitting, and re-assembly — which is exactly what a citation needs.

For general-purpose stamping — dates, draft markings, confidentiality banners, logos — the same footer/header machinery applies; see adding headers and footers to PDFs and watermarking.

The rest of the production toolkit, free on the PDF Hub

Bates numbering is rarely the only step in preparing a production, and the Mapsoft PDF Hub covers the neighbouring jobs in the same browser session, free:

• Redact PDF — permanently remove privileged or personal content before stamping.
• Merge PDFs and Remove Pages — assemble the final page set in production order.
• Add Page Numbers, Add Headers & Footers, and Add Watermark — ordinary numbering, running titles, and DRAFT/CONFIDENTIAL overlays.
• Flatten Annotations and Sanitize PDF — bake markup into the page and strip hidden data before the file leaves the building.

For recurring productions, the Hub's Workflow Builder chains these operations into a repeatable pipeline, and the same operations are available programmatically through the REST API.

Frequently asked questions

What is Bates numbering, in one sentence?

A unique sequential identifier — prefix, zero-padded number, optional suffix — stamped on every page of a document set so any page can be cited unambiguously.

Why is it called “Bates”?

After the Bates Automatic Numbering-Machine, an 1890s self-advancing hand stamp from the Bates Manufacturing Company of New York. The stamp is obsolete; the name stuck.

Is Bates numbering legally required?

No law requires it by name, but courts require page-level identification of produced documents, and Bates numbering is the accepted mechanism — protective orders and discovery agreements frequently specify it outright.

Can I number several PDFs with one continuous sequence?

Yes — merge them first and stamp once, or stamp them one at a time with each file's starting number continuing where the previous file ended. For high volumes, Acrobat Pro or a batch plugin like Impress Pro stamps across many files in one operation.

Does the stamp alter my document?

The identifier is added to the page margin as new content; the document text itself is untouched. Stamp the production copy and keep the unstamped original in your records.

Can Bates numbers be removed?

Once stamped and flattened into the page they are part of the content, and that permanence is intentional. Treat stamping as one-way: if the numbering is wrong, go back to the unstamped original and stamp again.