In e-discovery, Bates numbering assigns a unique identifier to each produced page so it can be tracked under FRCP 34's requirement that productions be organized and identifiable. Review platforms often layer internal control numbers on top of a Bates number, and native files may receive a document-level control number instead of page-level imaging. The format is normally fixed in an ESI protocol agreed between the parties before the first volume ships, covering the prefix, the digit width, where the stamp sits on the page, and whether confidentiality designations are endorsed alongside the number. Because opposing counsel, experts and the court will cite pages by that identifier for the life of the matter, the sequence must run continuously across every file in a volume and must never reuse a number burned in an earlier production. Most teams record the first and last identifier of each document in a range ledger, then reconcile that ledger against the delivered files before the volume leaves the building.
This guide explains legal Bates workflows. BatesFast applies the identifiers; it does not replace review, redaction, or production validation.
Where Bates Numbering Fits Under FRCP 34
Federal Rule of Civil Procedure 34 governs requests for production of documents and electronically stored information. The rule itself does not use the word "Bates" anywhere; instead it requires that a responding party produce documents as they are kept in the ordinary course of business, or organize and label them to correspond with the categories in the request.
“A party must produce documents as they are kept in the usual course of business or must organize and label them to correspond to the categories in the request.”
Fed. R. Civ. P. 34(b)(2)(E)(i)
Bates numbering is the practical, industry-standard mechanism litigants use to satisfy that labeling requirement at scale. A continuous numbered sequence gives every party, and the court, a stable way to refer to specific pages in motions, deposition exhibits, and privilege logs, without which "organized and labeled" would be difficult to demonstrate in a production of any real size.
Bates Numbers vs Control Numbers in Review Platforms
Document-review platforms typically assign their own internal control number, sometimes called a document ID, to every record loaded into the database. This number exists purely for internal tracking during review and coding; it usually has nothing to do with what will eventually be stamped on the page once a document is selected for production.
A Bates number, by contrast, is assigned at production time and appears on the actual produced page or in the metadata load file that accompanies it. It is entirely normal for a single document to carry an internal control number throughout the review workflow and then receive a separate, unrelated Bates number the moment it crosses over into a formal production.
| Identifier | Assigned when | Visible to | Typical use |
|---|---|---|---|
| Control number | At ingestion into the review platform | Internal review team only | Tracking, coding, and QC inside the database |
| Bates number | At production | All parties and the court | Citation in briefs, exhibits, and depositions |
| Custodian / source ID | At collection | Internal review team only | Tracing a document back to its original custodian |
Native Files vs Imaged Productions
Imaged productions convert every page of every document into a static image, typically a TIFF or a PDF page, and a Bates number is stamped directly onto that image. This is the traditional approach and makes the identifier permanent and visible even when the page is printed on paper.
Native productions instead hand over the original file format — an Excel workbook, a PowerPoint deck, an email in its original container — without converting it to a page image. Because there is no fixed page to stamp, native files are usually tracked with a document-level Bates or control number recorded in the accompanying load file, sometimes paired with a single placeholder slip-sheet image bearing that same number so the file has a physical stand-in on the production log.
Page-Level Numbering vs Document-Level Numbering
Page-level numbering assigns a distinct Bates number to every single page, which is the norm for imaged productions: a 40-page contract consumes 40 consecutive numbers. Document-level numbering instead assigns one identifier to an entire file regardless of how many pages or records it contains, which is common for native productions and for certain structured data exports.
The choice affects how citations work later in the case. Page-level numbers let counsel cite an exact page ("see SMITH-002419"), while a document-level number requires an additional pointer, such as a page or tab reference within the file, to reach the same precision.
Rolling Productions and Numbering Continuity
Most matters of any size are not produced in a single batch. Instead, documents go out in a series of rolling productions as review completes on successive custodians or date ranges, sometimes over months. Numbering continuity across those rounds is what lets a citation stay stable for the life of the case: a page cited as SMITH-014208 in month two should still be SMITH-014208 if anyone needs to reference it in month eight.
Maintaining that continuity means tracking the last number used at the end of each round and picking up exactly where the sequence left off for the next one, rather than letting each vendor or reviewer start over. When productions involve multiple outside vendors handling different custodians, someone on the litigation-support side needs to own the master sequence and hand out number ranges, the same way a printer manages signature ranges across a multi-vendor print run, so two rounds never collide on the same number.
Supplemental and corrective productions add another wrinkle. If a page was withheld in error and produced later, it typically receives a new Bates number rather than retroactively claiming a number from the original sequence, with a cover note or production log explaining the correction. Reusing an old number for a different page, even to "fix" an omission, reintroduces exactly the ambiguity Bates numbering exists to prevent.
What Does the Receiving Party Do With the Volume?
They load it, which is why the deliverable is a package rather than a set of files. The images, the extracted or recognised text, the load file describing the documents and the natives all have to arrive together and agree with each other, or the import stops.
Their platform then indexes the volume against the identifiers you supplied, and every subsequent reference in the matter resolves through that index. A range that disagrees between the load file and the images produces documents that exist but cannot be cited reliably.
This is the practical reason format disputes are worth settling early. The receiving party's workflow is built around a specific shape of deliverable, and a volume that does not fit it generates a re-production request rather than a workaround.
Common questions
Does FRCP require Bates numbering by name?
No. Federal Rule of Civil Procedure 34 requires that a party producing documents either produce them as kept in the usual course of business or organize and label them to correspond with the request categories. Bates numbering is the accepted, though not literally mandated, way litigation practice satisfies that labeling requirement.
What is a control number in a review platform?
A control number is an internal identifier a document-review platform assigns to a document or record within its own database, independent of any Bates number that may later be stamped when the document is produced. A single document can carry a control number for internal tracking and a separate Bates number once produced.
How are native files, such as spreadsheets, numbered without converting them to an image?
A native file that is produced in its original format typically receives a document-level control or Bates number referenced in a metadata load file and often via a placeholder image, rather than a number burned onto every internal page, since the file itself is never rendered to a fixed page image.
Can Bates numbers be reused between separate productions in the same case?
Not without creating ambiguity. Best practice is to continue a single running sequence across every production in a matter, or to use clearly distinct prefixes per production round, so that no two rounds ever generate an identical citation string.
Is the Bates number applied to the native file or the image?
To the rendered image. For electronically stored information the number is stamped on the produced PDF or TIFF, while native files are produced alongside with their Bates range recorded in the load file, commonly with a placeholder image carrying the beginning number and any confidentiality designation.
How are email families numbered?
Parent messages and their attachments are normally kept together and numbered consecutively, so the family occupies one continuous range. Preserving that adjacency is what allows a reviewer to see which attachment belongs to which message after the production has been split across volumes.
Further reading: Federal Rule of Civil Procedure 34 — Cornell Legal Information Institute.