LEDES 1998B Format: All 24 Fields Explained (with Example)
LEDES 1998B is the plain-text invoice format most US corporate legal departments and insurers require for e-billing. It's a pipe-delimited (|) file with one line per fee or expense, and the invoice-level data repeated on every line.
File structure
- Line 1 is exactly
LEDES1998B[]. - Line 2 is the header: the 24 field names below, separated by
|, ending in[]. - Every following line is one line item with 24 values, ending in
[].
Dates are YYYYMMDD. Numbers have no currency signs or thousands separators. Text should be plain ASCII with no pipes or line breaks. Several invoices can share one file; lines are grouped by INVOICE_NUMBER.
The 24 fields
| # | Field | What goes in it | Required |
|---|---|---|---|
| 1 | INVOICE_DATE | Invoice date, YYYYMMDD. | Yes |
| 2 | INVOICE_NUMBER | Your invoice number (max 20). Same on every line of the invoice. | Yes |
| 3 | CLIENT_ID | Your firm's ID for the client (max 20). | Yes |
| 4 | LAW_FIRM_MATTER_ID | Your firm's matter number (max 20). | Yes |
| 5 | INVOICE_TOTAL | Sum of all LINE_ITEM_TOTAL values for the invoice. | Yes |
| 6 | BILLING_START_DATE | First day of the billing period, YYYYMMDD. | Yes |
| 7 | BILLING_END_DATE | Last day of the billing period, YYYYMMDD. | Yes |
| 8 | INVOICE_DESCRIPTION | Short description of the invoice (max 2000). | Recommended |
| 9 | LINE_ITEM_NUMBER | Line number, unique within the invoice. | Yes |
| 10 | EXP/FEE/INV_ADJ_TYPE | F = fee, E = expense, IF / IE = invoice-level fee or expense adjustment. | Yes |
| 11 | LINE_ITEM_NUMBER_OF_UNITS | Hours for fees (e.g. 1.5), quantity for expenses. Must be greater than 0. | Yes |
| 12 | LINE_ITEM_ADJUSTMENT_AMOUNT | Discount (negative) or premium on the line, in currency. | Optional |
| 13 | LINE_ITEM_TOTAL | Units × unit cost + adjustment, 2 decimals. | Yes |
| 14 | LINE_ITEM_DATE | Date of the work or expense, YYYYMMDD, inside the billing period. | Yes |
| 15 | LINE_ITEM_TASK_CODE | UTBMS task code for fees, e.g. L120. | Fees |
| 16 | LINE_ITEM_EXPENSE_CODE | UTBMS expense code, e.g. E101. | Expenses |
| 17 | LINE_ITEM_ACTIVITY_CODE | UTBMS activity code for fees, e.g. A104. | Fees (usually) |
| 18 | TIMEKEEPER_ID | Unique ID for the person billing (initials or employee number; some portals allow 8 characters). | Fees |
| 19 | LINE_ITEM_DESCRIPTION | Narrative for the entry (max 2000), plain ASCII. | Yes |
| 20 | LAW_FIRM_ID | Your firm's ID, normally the tax ID (EIN) as NN-NNNNNNN. | Yes |
| 21 | LINE_ITEM_UNIT_COST | Hourly rate for fees, unit price for expenses. | Yes |
| 22 | TIMEKEEPER_NAME | "Last, First" (max 30). | Fees |
| 23 | TIMEKEEPER_CLASSIFICATION | PT partner, AS associate, OC of counsel, LA legal assistant / paralegal, OT other. | Fees |
| 24 | CLIENT_MATTER_ID | The client's own matter, claim or file number (max 20). | Usually |
The math portals check
LINE_ITEM_TOTAL = LINE_ITEM_NUMBER_OF_UNITS × LINE_ITEM_UNIT_COST + LINE_ITEM_ADJUSTMENT_AMOUNT, rounded to cents. INVOICE_TOTAL must equal the sum of the line totals and be the same on every line. A one-cent difference is enough for a rejection.
Example line
20261031|INV-1001|ACME|2026-014|675.00|20261001|20261031|Legal services October 2026|1|F|1.50|0|675.00|20261002|L120||A104|NB|Review and analyze complaint|12-3456789|450|Bell, Nora|PT|CLM-44-1021[]
1998B vs 1998BI and XML
LEDES 1998BI (international) adds tax, currency and address fields; LEDES XML 2.x is a structured XML format. Most US insurers and corporate clients still ask for 1998B, which is what LedesReady creates and validates.