---
title: "Build a draft invoice from the time records and the engagement terms"
url: "https://ailawframework.com/obligations/costs-billing-and-litigation-funding/build-a-draft-bill-from-the-time-records-and-the-disclosure/united-states"
type: "task_jurisdiction_version"
site: "AI Law Framework"
id: "A42-A20260923-1-US"
practice_area: "Costs, billing & litigation funding"
tier: "yellow"
lawyer_review: "required"
jurisdictions: ["US"]
last_reviewed: "2026-10-22"
---

# Build a draft invoice from the time records and the engagement terms

> From the time entries and the engagement letter the lawyer supplies, list each entry, the time recorded, and the rate or fee basis the letter states. Do not invent time or write the invoice that will be sent.

Canonical page: https://ailawframework.com/obligations/costs-billing-and-litigation-funding/build-a-draft-bill-from-the-time-records-and-the-disclosure/united-states  
Last reviewed: 2026-10-22

Site index for agents: https://ailawframework.com/llms.txt

## Key facts

| Fact | Value |
| --- | --- |
| Practice area | [Costs, billing & litigation funding](https://ailawframework.com/obligations/costs-billing-and-litigation-funding.md) |
| Human involvement | Yellow: Lawyer and AI draft together |
| How AI is used | From the time entries and the engagement letter the lawyer supplies, list each entry, the time recorded, and the rate or fee basis the letter states. Do not invent time or write the invoice that will be sent. |
| What the lawyer must review | Model Rule 1.5(a) forbids an unreasonable fee. Rule 1.5(b) requires the scope and the basis or rate of the fee and expenses to be communicated to the client, preferably in writing, before or within a reasonable time after the representation starts, and any change in that basis or rate to be communicated as well. Formal Opinion 512: a lawyer who bills by the hour must bill actual time, including time spent prompting a tool and reviewing its output, and must not bill hours the tool saved. The lawyer matches every line to the records and the current engagement terms before anything is sent. |
| Written for | United States |
| Applies to | [Build a draft bill from the time records and the disclosure](https://ailawframework.com/obligations/costs-billing-and-litigation-funding/build-a-draft-bill-from-the-time-records-and-the-disclosure.md) |

## Checking plan

- What the AI does: From the time entries and the engagement letter the lawyer supplies, list each entry, the time recorded, and the rate or fee basis the letter states. Do not invent time or write the invoice that will be sent.
- Basis: Checked against the linked sources on 22 October 2026. Confirm the current instrument before reliance.

## Notes

- There is no national scale of costs. State rules of professional conduct, and any written fee statute in that state, control over the Model Rule.
- California’s 2026 practical guidance: hourly bills reflect time actually spent, and the fee agreement should say how generative-AI use affects fees and costs.

## Sources

- [ABA Model Rule 1.5, Fees](https://www.americanbar.org/groups/professional_responsibility/publications/model_rules_of_professional_conduct/rule_1_5_fees/) (checked 2026-10-22)
- [ABA Formal Opinion 512, Generative Artificial Intelligence Tools (29 July 2024)](https://www.americanbar.org/content/dam/aba/administrative/professional_responsibility/ethics-opinions/aba-formal-opinion-512.pdf) (checked 2026-10-22)
- [State Bar of California, Practical Guidance for the Use of Generative Artificial Intelligence in the Practice of Law (2026 update)](https://www.calbar.ca.gov/Portals/0/documents/ethics/Generative-AI-Practical-Guidance.pdf) (checked 2026-10-22)

## Forms and precedents for this task

| Form or precedent | Kind | AI level | Summary |
| --- | --- | --- | --- |
| [Engagement letter with a generative AI clause (United States)](https://ailawframework.com/precedents/costs-billing-and-litigation-funding/us-engagement-letter-generative-ai.md) | Letter | Yellow | Engagement letter stating the scope and the basis of the fee, and separating ordinary generative-AI use from any input of information relating to the representation, which needs a completed tool… |
| [Itemised bill and letter answering a request for one](https://ailawframework.com/precedents/costs-billing-and-litigation-funding/itemised-bill.md) | Letter | Yellow | Covering letter and itemised bill in answer to a request made after a lump sum bill, with the 30-day request period and the 21-day response period, and a named responsible principal. |
| [Timekeeper check before billing generative AI work (United States)](https://ailawframework.com/precedents/costs-billing-and-litigation-funding/us-timekeeper-gai-billing-check.md) | Checklist | Yellow | A check a timekeeper completes before AI-assisted time or a per-use AI charge is put on a bill, so the bill reflects time actually spent and expenses the engagement allows. |
| [Worksheet comparing a draft bill with the costs disclosure](https://ailawframework.com/precedents/costs-billing-and-litigation-funding/bill-disclosure-comparison.md) | Checklist | Yellow | Internal worksheet that sets a draft bill beside the last costs estimate, later updates, uplift and AI-assisted time, before the bill is sent. |

Signed-in accounts can read the full text of each one.

*Practice guidance for planning and review. Confirm current primary sources and the requirements of the actual matter. This is general information, not legal advice.*