A law firm should invoice with itemized time entries, a clear matter reference and an agreed billing rhythm. Most firms need four documents: the invoice, a receipt for payments, a credit note for corrections and an account statement for retainer balances.
Documents legal practices use
- Invoice. Send it at the end of each billing period or at a matter milestone. List each task as a line item with hours as the quantity and your rate as the unit price. Put the matter reference in Notes.
- Receipt. Send it when a client pays, especially for a fixed fee or a cash payment. It confirms the amount and the date.
- Credit note. Use it when you write off time, fix a rate error or refund an overpayment. It keeps the original invoice intact.
- Account statement. Use it to show a client the retainer received, the fees applied and the balance left.
The generators do not store data. Download each PDF and save it in the matter file.
How billing usually works
| Model | How it works | Watch for |
|---|---|---|
| Hourly | Time entries multiplied by a rate | Vague task descriptions |
| Fixed fee | One agreed price for a defined scope | Scope that grows |
| Retainer | Client pays in advance, fees draw it down | Rules on advance funds |
| Contingency | Fee depends on the outcome | Local rules and written terms |
Time capture drives accuracy. Record time as you work, not at month end. See timesheets for billing for a simple method.
Retainer funds raise regulatory questions. In many places, client money must stay in a separate account. Rules differ by jurisdiction, so ask your bar association or regulator. These tools only produce documents.
Common invoicing mistakes
- Lumping hours into one line such as "Legal services".
- Leaving out the matter reference, which makes the client's payment hard to match.
- Billing in rounded blocks without telling the client in the engagement letter.
- Editing a sent invoice instead of issuing a credit note.
- Mixing retainer deposits with earned fees on one document.
- Sending no due date or late-fee terms. Read about invoice late fees before you add any.
Useful calculators and guides
- Retainer calculator to size a retainer.
- Billable hours calculator to total time entries.
- Hourly invoice calculator to price a bill.
- Late payment interest calculator to check what a late balance costs.
Guides: retainer agreements, how to invoice a client and collecting unpaid invoices.
Frequently asked questions
- What should a legal invoice include?
- Include the matter name or reference, the date range, each task with time spent and rate, any expenses, tax if it applies, the total and the due date. Clients read legal bills closely, so clear task descriptions prevent questions.
- Can I use these tools for client trust account funds?
- The tools create documents only. They do not hold or track money. Rules for client trust accounts vary by jurisdiction. Ask your bar association or regulator how to record and report deposits.
- How do I bill a retainer?
- Agree the retainer amount and its purpose in writing. Then show a statement with funds received, fees applied and the remaining balance. Rules on advance fees differ by jurisdiction, so check with your bar before you set up the process.
- How do I correct an invoice I already sent?
- Do not edit the sent invoice. Issue a credit note that references the original invoice number and states the reason. Then send a new corrected invoice with its own number.
- How often should a law firm invoice?
- Monthly is common for ongoing matters. Some firms bill at milestones, such as filing or closing. Pick a rhythm, write it in the engagement letter and keep to it.