Quarterly Outside Counsel Spend Summary: A Four-Prompt Chain in Claude

What This Builds

A half-page spend summary for your GC or CFO, built in four steps inside one Claude conversation. First Claude checks the arithmetic in your totals. Then it compares each matter with its budget. Then it drafts the summary with the three largest variances and a blank column for your reasons. Last, it drafts the questions to raise with each firm. You check the numbers against your source sheet after every step.

The reasons behind a variance are yours to write. Claude does the arithmetic and the formatting.

Prerequisites

• A Pro plan ($20/month), or the Claude plan your company has approved for confidential and privileged work
• A sheet with the quarter's totals by matter code and firm, and a budget for each matter
• Total ongoing cost: the Claude plan above, with nothing else to buy

Data note. Use only the AI tool your company has approved, and check its data settings: training on chats, retention, and who at the company can see them. Paste matter codes, "Firm A" and "Firm B", and rounded totals only. Never paste invoice narratives, because time entries can describe privileged work. Replace firm names, strip lawyer names, and leave out any detail that identifies a dispute. Keep the key from codes to real matters in your own files. Follow your company's policy and your state bar's guidance on what may go into an AI tool.

The Concept

Think of a second pair of hands at the end of a close. You give them the totals. They re-add every column, flag what does not tie and build the comparison table, and only then do they write anything. Checking the arithmetic first matters because every later step depends on those numbers. A small error in a matter total becomes a wrong variance, a wrong summary, and an awkward question to a firm.

Build It Step by Step

Part 1: Prepare the table

Build a plain table with one row per matter code. For each matter, list the monthly or invoice-level totals for the quarter, rounded, the total as stated on your sheet, and the budget. Use "Firm A" and "Firm B" for firm names. The example below uses invented round numbers with no currency, in one consistent unit.

Stated firm totals on the sheet: Firm A 320, Firm B 105.

Check it yourself first. M-101 is 40 plus 55 plus 35, which is 130. M-102 is 60 plus 70 plus 50, which is 180, so the stated 190 is wrong by 10. M-103 is 75 and M-104 is 30. Firm A is 130 plus 180, which is 310, against a stated 320. Firm B is 75 plus 30, which is 105. The planted mismatch is there so you can see the chain catch it.

Part 2: Prompt 1, check the arithmetic

Start a new conversation and send:

Here is a table of outside counsel spend for one quarter by matter code and firm. For each matter, add the line items and compare the sum with the stated total. Then add the matter sums by firm and compare with the stated firm totals. Show the working for each sum. List every mismatch with the stated figure, the computed figure and the difference. Do not correct the stated figures. Do not assume which figure is right.

[Paste the table and the stated firm totals here]

Checkpoint 1. Re-add every line yourself against the source sheet. Claude should report one matter mismatch and one firm mismatch: M-102 computed 180 against stated 190 (difference 10), and Firm A computed 310 against stated 320 (difference 10). Open the invoices and decide which figure is right. In the example the line items are right, so use 180. Reply "Use the computed figures. M-102 is 180 and Firm A is 310." before moving on.

Part 3: Prompt 2, compare with budget

Using the corrected totals, build a table with one row per matter: matter, firm, spend, budget, difference (spend minus budget, positive when over budget), and share of budget used (spend divided by budget, as a decimal to two places). Add a total row for all matters. Show the arithmetic for each row.

Budgets: [paste the budget for each matter]

Expected result for the example:

The totals check out: 130 plus 180 plus 75 plus 30 is 415, and 125 plus 200 plus 50 plus 40 is 415.

Checkpoint 2. Recompute each difference and share on your own calculator. Confirm the total row. Compare the spend column with your source sheet. Do not go on until every figure matches.

Part 4: Prompt 3, the half-page summary

Draft a half-page spend summary for [the GC or the CFO] covering [quarter]. Include: total spend against total budget, the three matters with the largest variance in absolute size (state the difference and the share of budget used), and a table with the columns Matter, Firm, Spend, Budget, Difference, Reason. Leave the Reason column empty for me to fill in. Do not guess reasons. Keep it to half a page and use only the figures in the table above.

In the example the three largest variances are M-103 (+25), M-102 (-20) and M-104 (-10). M-101 at +5 is the smallest.

Checkpoint 3. Check every number in the draft against the Part 3 table and the source sheet. Fill in the Reason column yourself, drawing on what you know about each matter and, where needed, a call to the firm. Reasons based on privileged strategy stay out of a document that goes to the CFO unless your company's practice allows it. Do not let Claude invent a reason.

Part 5: Prompt 4, questions for each firm

Draft the questions I should raise with each firm about this quarter's spend. Use only the matter codes, firm labels and figures in the table. For each firm, list the matters over budget first, then those under budget, and one or two questions per matter, for example about the forecast to completion, what drove the difference, and whether the budget needs revising. Keep the tone professional and neutral.

Checkpoint 4. Read each question and cut anything that assumes a reason. Replace "Firm A" and "Firm B" and the matter codes with the real names yourself before you use the questions. Nothing is sent to a firm by Claude. You decide what to raise and when.

Real Example: The Quarter in the Table

Setup: The four invented matters above. Input: The table and stated firm totals go into prompt 1. Output: Prompt 1 flags the M-102 and Firm A mismatches. You confirm 180 and 310 from the invoices. Prompt 2 returns the budget table with total spend 415 against budget 415. Prompt 3 drafts the summary around M-103, M-102 and M-104 and leaves Reason blank. You fill in "scope expanded" for M-103 after a call with the matter lead, and write nothing privileged. Prompt 4 gives Firm B a question on the forecast for M-103, and Firm A a question on the M-102 total that did not add up. Time saved: The re-adding and the table building. Estimate your own figure after a quarter.

What to Do When It Breaks

• Claude's sums do not match yours → Ask it to show every addition, then find the first line that differs. Trust your own recalculation and the source sheet over the chat.
• Claude "corrects" a stated figure silently → Repeat prompt 1 with the instruction to report mismatches without correcting them.
• A variance reason appears that you did not supply → Delete it. The Reason column is yours.
• The summary uses a number that is not in the table → Ask Claude to cite the table row for each figure, and remove any it cannot.
• Share of budget looks off for a matter with no budget → Add the budget or take the matter out of the table.

Variations

• Simpler version: Run prompts 1 and 2 only and write the summary yourself.
• Extended version: Save the four prompts as a Claude Project's instructions so each quarter you only paste a new table.

What to Do Next

• This week: Run the chain on last quarter's figures, where you already know the answers.
• This month: Add a column for forecast to completion.
• Advanced: Keep the table in a sheet and paste a fresh copy each quarter.

Advanced guide for corporate attorney professionals. These techniques use more sophisticated AI features that may require paid subscriptions. AI output is a first draft. You check every figure against the source and remain responsible for what goes to the GC or CFO.