Bates Numbering for Legal Documents

Bates numbering — also called Bates stamping, Bates coding, or Bates labeling — applies a unique, sequential identifier to each page in a set of documents. The identifier prints in a consistent spot, most often the bottom-right corner, and increases by one on every page. Because each number appears only once across the whole set, any page can be cited unambiguously.

The name comes from Edwin G. Bates, who in the 1890s patented a self-incrementing hand stamp that became known as the Bates Automatic Numbering Machine. Each press printed a number and advanced to the next, making it fast to number long paper files. Law firms adopted the device for case documents, and the name stuck long after the process moved to software.

Today Bates numbering is applied digitally. Rather than ink-stamping paper, e-discovery and PDF tools burn the identifier into image or PDF pages as an endorsement, making it a permanent, printable part of the document rather than editable metadata.

A Bates number almost always has two parts: an alphabetic prefix followed by a zero-padded numeric sequence, sometimes joined by a hyphen or underscore. Typical labels look like ABC-000123 or SMITH00004567. The prefix identifies the case, the producing party, or a document custodian; the number is the running count.

Zero-padding — the leading zeros in 000123 — keeps every label the same length so numbers sort correctly and stay visually aligned, and it reserves room for the full expected volume. A six-digit pad covers up to 999,999 pages; large productions often use seven or eight digits to avoid running out and having to renumber.

Some labels add a confidentiality legend or a second endorsement, so a fully stamped page might read ABC-000123 CONFIDENTIAL. The Bates number and the confidentiality designation are separate, but they are commonly applied together in the same pass.

In litigation, thousands or even millions of pages change hands during discovery. Bates numbers give every party a shared, precise vocabulary: instead of 'the third invoice in the second folder,' counsel cites 'ABC-000456' and everyone knows the exact page. This precision underpins depositions, motions, exhibits, and trial references.

When a document spans several pages, it is identified by a Bates range — from the first page (the beginning Bates) to the last (the ending Bates), such as ABC-000456 to ABC-000461. Ranges reference a whole document while still pinpointing individual pages. E-discovery load files store these as BegBates and EndBates fields.

Bates numbers also create an audit trail. Because the sequence is continuous, gaps can signal that documents were withheld — for example as privileged — which are then accounted for on a privilege log. This traceability is why courts and opposing counsel expect produced documents to be Bates-labeled.

In modern e-discovery, Bates numbers are applied programmatically across an entire production at once. The software walks through every document in order and stamps pages continuously, so the count carries across document boundaries rather than restarting for each file. A 50,000-page production is numbered as one unbroken sequence.

Productions often go out in rolling batches. To stay consistent, teams either continue the sequence from where the last batch ended or reserve number blocks in advance. The endorsement sits in the same corner on every page, sized so it never covers text, and it is burned into the page image so it survives printing and copying.

Alongside the stamped pages, a load file — in formats such as DAT or OPT — maps each document to its Bates range and links it to metadata and native files. A DAT file typically carries delimited, document-level metadata, while an OPT file cross-references the individual page images. This lets review platforms retrieve any document by its Bates number instantly.

Consistency is what makes a Bates set reliable. Use a single, meaningful prefix per producing party so the source of any page is obvious at a glance, and pick a padding width generous enough for the entire matter before you start. Renumbering a production afterward is disruptive because prior citations no longer point to the right pages.

Every number must be unique at the page level. Don't reuse or skip numbers arbitrarily, keep the stamp in a fixed corner, and maintain a Bates log so ranges trace back to custodians and documents. These habits keep the production defensible if its integrity is ever questioned.

Confidentiality designations are frequently stamped alongside Bates numbers under a protective order. Common legends include CONFIDENTIAL and HIGHLY CONFIDENTIAL – ATTORNEYS' EYES ONLY. They control who may view a document and are distinct from the Bates number, even though both endorsements usually appear on the same page.

Page numbers and Bates numbers solve different problems. A page number marks a page's position within a single document and restarts at 1 for the next document, so the same 'page 3' can exist in hundreds of files. It answers 'where am I in this document?'

A Bates number is globally unique across an entire production and never repeats. It answers 'which specific page in the whole case is this?' Two documents can both have a page 3, but only one page anywhere can be ABC-000003.

Because Bates numbers are permanent, sequential, and unique, they serve as durable identifiers for legal reference, while ordinary page numbers stay a within-document convenience. Well-organized productions often show both.