Bates numbers explained: what they are and how they work

What a Bates number is

A Bates number is a unique identifier stamped on every page of a set of documents, usually in a corner at the bottom. It's most common in legal work — when documents are exchanged between parties in a dispute, filed as exhibits or reviewed by several people — but the same approach is used for audits, insurance claims and any large archive where pages must be cited precisely.

The name comes from the Bates numbering machine, a hand stamp that printed a number and then moved on to the next one automatically. Today the stamping is done digitally, but the idea is unchanged: once a page has a number, anyone can say 'see ACME000417' and everyone finds the same page, regardless of which file, folder or binder it ended up in.

The anatomy of a Bates number

Most Bates numbers have two parts: a prefix and a zero-padded counter. In SMITH-000123, 'SMITH-' is the prefix and '000123' is the page's place in the sequence.

• The prefix usually identifies who produced the documents, the case or the batch — a party's name, initials or a short code. It stops numbers from different sources being confused.
• Zero padding keeps every number the same length. 000009 and 000010 sort correctly as text, look tidy in a list, and make the size of the set obvious at a glance.
• The sequence never restarts. Numbering runs across every page of every document in the set, so no two pages share a number. A second batch typically continues from where the first ended.
• Every page counts, including blank pages, cover sheets and exhibit slip sheets — a gap in the sequence makes people wonder what's missing.

Tip: Choose enough digits for the whole set before you start. Six digits allows up to 999,999 pages; a number that grows past the padding becomes longer than the others and breaks the tidy sorting.

Exact formats — the prefix, whether there's a hyphen or space, the number of digits and where the stamp goes — are often set by an agreement, a court's rules or the person asking for the documents. If a format has been specified, follow it; this guide explains the conventions, not what any particular rule requires.

Bates numbers vs page numbers vs headers and footers

They aren't exclusive. A document can keep its own printed page numbers — '3 of 12' in the footer — and still carry a Bates number in the corner. The page number tells you where you are in that document; the Bates number tells you where you are in the whole set.

Adding Bates numbers to PDFs

Bates Numbering stamps your prefix and a zero-padded counter on every page. You choose the prefix (up to 20 characters, using Latin letters, digits and common punctuation), the starting number (anything up to 99,999,999, handy for continuing an earlier production), the number of digits from 1 to 10, and the position: bottom left, bottom centre or bottom right.

1. Add up to 50 PDFs and drag them into production order — numbering follows the list.
2. Set the prefix, the starting number and the digits. With prefix SMITH- and 6 digits, the first page reads SMITH-000001.
3. Run it. The second PDF starts where the first ended, and so on through the list.
4. Download the stamped files — each keeps its name with _bates added — individually or together as a ZIP.

Each number is printed in black, 9 pt bold type, about 6 mm above the bottom edge. It's placed on the page as a viewer shows it, so it stays upright on rotated pages, and it becomes part of the page content rather than a removable comment.

One file or many?

Because numbering continues from file to file, you don't need to combine documents first; keeping them separate makes it easy to refer to each one by its first and last Bates number. If the recipient wants a single PDF instead, Merge PDF the files in production order first, then number the merged file once.

Either way, settle the order and content before stamping. Adding or removing a page afterwards means renumbering everything that follows, which defeats the point of a fixed reference. Keep an unstamped copy of the originals too.