What this law firm actually buys
Separate general assistants used for drafting or internal work from specialist legal research, document review and practice-management AI. A specialist subscription may be priced by user, matter, document volume or agreement; copy the actual billing model from its order form rather than applying a general-assistant seat price.
Assign each subscription to a workflow and a matter-staffing role. Ask the person responsible for the firm's confidentiality policy which information the approved workflow may use. This is a review question for the firm, not legal advice or a claim that buying a particular plan makes client-data use permissible.
AI costs for law firms: what the bill looks like
Illustrative example: a fictional 25-person law firm assigns 10 ChatGPT Business Standard seats and gives five of those same people a Copilot Business add-on. That is 15 paid subscriptions across 10 people, not 10 paid subscriptions.
| Purchased capacity | Formula | Annual seat charge |
|---|---|---|
| ChatGPT Business Standard | 10 × US$20 × 12 | US$2,400 |
| Copilot Business add-on | 5 × US$21 × 12 | US$1,260 |
| Combined seat charges | US$2,400 + US$1,260 | US$3,660 |
The rates are monthly equivalents under annual billing or commitment. The total excludes required Microsoft base licenses, extra workspace or API usage, taxes and specialist legal tools. If base licenses are already in the technology budget, identify that existing commitment instead of counting it twice.
Source verified October 29, 2026: OpenAI, ChatGPT Business overview.
Source verified October 29, 2026: Microsoft, Microsoft 365 Copilot business pricing.
| Firm headcount | Assumed seat mix | Annual seat formula |
|---|---|---|
| 10 | 4 ChatGPT + 2 Copilot | (4 × US$20 + 2 × US$21) × 12 = US$1,464 |
| 25 | 10 ChatGPT + 5 Copilot | (10 × US$20 + 5 × US$21) × 12 = US$3,660 |
| 100 | 40 ChatGPT + 20 Copilot | (40 × US$20 + 20 × US$21) × 12 = US$14,640 |
These paid-seat assumptions scale only to show the arithmetic. Your seat count follows justified access, usage follows actual workload, and base software follows the licenses your firm needs. Do not treat employee count as an automatic purchasing rule. AI seat versus usage pricing explains the distinction.
Estimate the seat commitment
Use separate counts for Standard and Premium seats. Formula: (Standard seats x Standard rate) + (Premium seats x Premium rate) = monthly equivalent; monthly equivalent x 12 = annual equivalent. A monthly plan's twelve-month total is a scenario, not an annual commitment.
Billing period
Review this estimate with the AI Renewal Checklist, or explore the AI Spend Control System for a manual working toolkit.
Excluded from the seat subtotal: taxes, API usage, workspace credits, extra usage and separate base licenses. Google Workspace is a complete suite price. Copilot uses its add-on list price, with its base license excluded unless the separate scenario is shown.
ChatGPT's current 200-seat limit applies to workspaces created from August 24, 2026; older workspaces retain their previous limit. Official seat-limit scope, verified October 29, 2026.
Optional base scenario: Microsoft 365 Business Standard with Teams, verified October 29, 2026. It is one eligible base plan; check the services already licensed and the dated Copilot terms above.
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Where renewals ambush this law firm
- Matter changes: paid capacity can remain after a matter closes, a temporary team disperses or a lawyer changes responsibilities. Reconcile purchased seats with the next period's work, not last quarter's staffing list.
- Research overlap: two subscriptions may support different checks. Ask the workflow owner what each contributes before treating overlapping features as redundant.
- Commitment timing: monthly invoices can sit inside an annual agreement. Confirm the actual notice method, seat-reduction effective date and data-export requirements before recording Retire.
A review for this law firm
Ask a responsible partner to sponsor the review and an operations owner to reconcile the invoice. Examine a defined period of work: who used the tool, what the output supported, what professional checking remained and whether the subscription is needed for the next matter mix.
Under billable-hour work, a faster draft is not automatically a financial gain. For fixed-fee work, lower preparation effort still needs to be assessed alongside checking and rework. Keep those observations separate from a savings or realization claim.
Record Keep for a supported ongoing workflow, Resize for justified capacity changes, Test for a bounded evaluation, or Retire with an approved transition and confirmed notice. The decision belongs to the firm; the checklist does not change any vendor account.
Use the ChatGPT cost for business and Copilot versus ChatGPT cost guides to inspect the billing detail.
First step
Choose one upcoming renewal and use the AI Renewal Checklist. Then build a record with the AI tool inventory template, confirm the contractual dates, and write the decision in the AI decision record.
Gather an invoice, the current agreement and a named workflow owner before comparing plans. The AI subscription audit guide explains how to check the inventory and finish the action.
Questions about the review
Should every employee get a paid AI seat?
No headcount rule substitutes for a workflow decision. Identify which lawyers and staff need the approved features, confirm the confidentiality boundary, and assign paid capacity to that work.
Do we need more than one AI assistant?
Only if the firm can explain the distinct work and required checks each supports. Review overlap at the matter or workflow level before removing access that an owner still needs.
Who should own the review in our firm?
An operations or finance owner can maintain the inventory, while a responsible partner approves the commercial decision. Include the people responsible for information handling and professional review when a workflow changes.
Turn the cost into a review decision
This illustrative example is a starting point for your own records. Start with one invoice and one upcoming renewal. Use the AI Renewal Checklist with no signup, then follow the AI subscription audit guide to build the wider review.
Keep the evidence, approver, notice deadline and Keep, Resize, Test or Retire decision in your own records or the free companion templates. These are not dedicated fields in the paid Control Center or workbook. Compare AI subscription review options if you need a different collection method.
The AccruePilot AI Spend Control System costs US$59 once for a local browser Control Center, editable Excel workbook and 12-page field guide. It is for one purchasing U.S. organization's internal use. Your team supplies and maintains the records; the toolkit does not discover accounts, enforce budgets or cancel services.
Start the free renewal checklist
Prepare an internal review email
Published by AccruePilot, which sells the manual toolkit discussed here. Vendor names identify the services reviewed and do not imply endorsement.