Bates numbering is the system that makes document production in litigation workable. Every page in a production set receives a unique sequential identifier, so any page can be cited unambiguously in a deposition, a motion, or at trial — years after it was produced, by people who were not involved in producing it.
The name comes from the Bates Automatic Numbering Machine, a nineteenth-century self-incrementing hand stamp. The mechanism has changed; the requirement has not.
What a Bates number looks like
A typical identifier combines a prefix with a zero-padded sequence:
- ABC000001 — a party or matter prefix followed by six digits
- SMITH-000042 — a party name with a separator
- DEF00001234 — a longer sequence for a large production
The prefix identifies the producing party or the matter. The padding keeps every identifier the same width, which matters more than it sounds: consistent width means identifiers sort correctly in a file listing, in a database, and in a spreadsheet.
Choosing your scheme before you start
Getting this right at the outset avoids painful renumbering later.
- Pick a prefix that identifies the producing party, not the document type. You will thank yourself when three parties' productions are sitting in the same folder.
- Pad generously. Six digits handles a million pages. Four digits looks tidy until the production hits page 10,000 and your sort order breaks.
- Never reuse a number. Each identifier must map to exactly one page for the life of the matter.
- Number the whole production, including blanks and slip sheets. Gaps in a sequence invite an accusation that pages were withheld.
- Record the range you produced. Note the first and last identifier in your cover letter and your privilege log.
The mistakes that cause disputes
The recurring problems in production are boring and avoidable.
Restarting the sequence for each document destroys the whole point — the numbering must run continuously across the production set, not per file.
Stamping over page content makes text unreadable and invites a request to re-produce. Place the stamp in a margin, conventionally the bottom right.
Inconsistent padding within one production — ABC1 followed by ABC000002 — breaks sorting and looks careless in a way opposing counsel will notice.
Numbering before the set is final. Add a document after stamping and you either renumber everything or produce an out-of-order set.
How to Bates stamp a PDF
- Assemble the production set. If it spans multiple files, merge them first so the sequence runs continuously.
- Set your prefix — the matter code or party abbreviation.
- Set the starting number and the padding width, producing identifiers like ABC000001.
- Choose the stamp position, keeping clear of page content.
- Export, then spot-check the first page, the last page, and a few in the middle.
The confidentiality problem with online stampers
Here is the part most guides skip. Discovery material is confidential by definition, frequently privileged, and often governed by a protective order that specifies exactly who may handle it.
Uploading that material to a free web service to have numbers stamped on it means transmitting it to a third party you have no agreement with, storing it on infrastructure you have not assessed, and retaining it for a window you do not control. If the other side asks how the production was prepared, "we uploaded it to a free website" is not an answer anyone wants to give.
Some firms have found this out the expensive way, and it is entirely avoidable.
Stamping without the upload
PDF Vault applies Bates numbering inside your browser. The document is read into local memory, stamped by WebAssembly running on your own machine, and written back to your downloads folder. Nothing is transmitted, logged, or retained by us, because there is no server component that could receive it.
That makes it appropriate for privileged material and for documents under a protective order, in a way that no upload-based service structurally can be. It also means it works on an air-gapped machine, which some firms require for particularly sensitive matters.
A practical workflow
For a typical production: merge the set into a single file, run Sanitize to strip metadata that could reveal internal authorship and timelines, apply Bates numbering, then spot-check the output before it goes out. Every step runs locally, so the document never leaves the machine it started on.