LEDES Billing Format Explained: Files, Codes and Rejections

Overview

LEDES (Legal Electronic Data Exchange Standard) is a family of standard file formats that law firms use to send invoices to corporate clients' e-billing systems. Most US clients ask for LEDES 1998B, a pipe-delimited text file, while the XML formats carry richer tax and currency detail. Each line is usually tagged with UTBMS task, activity and expense codes, and most rejections come from the client's billing guidelines rather than from the file layout.

This guide covers the formats, the codes and the checks that keep invoices from bouncing.

Download the LEDES Invoice Pre-Submission Cheatsheet (PDF, 1 page): a printable one-page check to run before an electronic invoice goes to a client.

What LEDES is and who maintains it

The standards are maintained by the LEDES Oversight Committee, a voluntary, not-for-profit group of legal industry representatives formed in 1995. Besides invoice formats, the committee publishes formats for budgets and timekeeper attributes, standard error codes, and the UTBMS code sets.

LEDES billing is narrower than e-billing. The LEDES file is only the envelope. The client's e-billing platform opens it, checks it against the format and against that client's own rules, and accepts or rejects lines. The legal e-billing software guide covers the platforms and the firm-side workflow around them; this article stays with the file and the reasons it gets sent back.

The main LEDES formats and who uses them

The format is the client's call. Their outside counsel guidelines or e-billing onboarding will name it, often down to the version, and a firm should not substitute a format it prefers.

The LEDES 1998B format page describes 1998B as the most widely used e-billing standard in the US legal industry and notes that the committee does not intend to modify it. That stability is why many billing systems produce 1998B well, and why clients with VAT or multi-currency needs move to 1998BI or XML.

Inside a LEDES 1998B file

A 1998B file starts with a line reading LEDES1998B, followed by a header row naming the 24 fields, then one row per invoice line. Fields are separated by a pipe character and each row ends with a pair of square brackets. Invoice-level values repeat on every row, which surprises people the first time they open one in a text editor.

The 24 fields fall into three groups:

• Invoice details: invoice date, invoice number, client ID, law firm matter ID, client matter ID, invoice total, billing start and end dates, and an invoice description.

• Line details: line number, line type (fee, expense or an adjustment), units, unit cost, adjustment amount, line total, line date, task code, expense code, activity code and line description.

• Firm and timekeeper details: law firm ID, timekeeper ID, timekeeper name and timekeeper classification.

Each value has to match what the client already holds. A matter ID that differs by one character, or a timekeeper ID the client has never seen, fails no matter how clean the rest of the file is.

Where UTBMS codes fit

UTBMS (Uniform Task-Based Management System) codes classify the work on each line. Task codes say what phase or task of the matter the work belongs to, activity codes say what the timekeeper did, and expense codes categorize disbursements. A litigation time entry might carry a task code for case analysis and strategy plus an activity code for drafting. Code sets exist for litigation, bankruptcy, counseling, projects, intellectual property and other work types, and each client chooses which ones it requires.

We have not reproduced the code lists here. MIRA's guide to UTBMS legal billing codes with examples lists the task, activity and expense codes with sample coded entries. Code at the time entry, not at invoice time: the timekeeper knows what the work was, and a billing clerk guessing codes a month later is a common source of rejections.

Why e-billing invoices get rejected

The LEDES Oversight Committee publishes standardized LEDES error codes; version 2, ratified in September 2024, identifies 65 errors and separates fatal errors that reject the whole file from validation and procedural errors on individual values. Not every client platform uses them yet, but they show the shape of the problem. In practice, most rejections trace back to a handful of causes.

Client guidelines add their own rules on top: caps on daily hours, limits on staffing at meetings, disallowed expense types, and billing deadlines. Those are not LEDES rules, but they arrive as LEDES rejections, so the billing team has to know them.

Fix rejections in the billing record

The tempting fix is to open the file, correct the value and resubmit. That clears today's rejection and guarantees the same one next month, because the billing record still holds the wrong code, rate or ID. It also leaves the firm's ledger and the client's accepted invoice disagreeing.

A steadier routine:

• Read the rejection reason and error code, line by line.

• Correct the time entry, rate table or matter setting that produced it.

• Regenerate the LEDES file from the corrected record.

• Resubmit and confirm acceptance on the client platform.

• Record the client rule so the next invoice is checked for it.

Partial rejections need the same discipline. If a client accepts an invoice but reduces lines, record the reduction as a write-down against the right lines so collections and realization reports match what was actually approved.

Pre-submission checklist

Run the check at pre-bill, while changes are still cheap. Each item needs an owner, and the evidence should be something a second person can verify.

The legal billing automation guide shows where these checks sit in an automated billing cycle, and the legal time and billing software guide covers capturing codes and narratives correctly at the time entry stage.

Where MATTEROOM fits

MATTEROOM's billing management page describes prebill tracking with matter-level budget, billable ratio and aging indicators, Smart Billing that automates invoices, reminders and bill approvals for hourly and retainer arrangements, multi-currency conversion into the billing currency, and a billing audit trail recording who changed what and when. Its project management page says the system supports industry-standard task codes as well as custom codes. Those are the record-level controls that prevent most of the rejections above.

E-billing and vendor management sit in MATTERLINQ, a separate product in the MATTEROOM family. Confirm with MATTEROOM which LEDES formats and versions the proposed setup produces, which UTBMS code sets it can enforce, and how a rejection from a client platform would flow back into the billing record. For the wider finance picture, see the law firm financial management software guide.