Audit what you pay for against what you use

What you need

• Your last three months of bank and business credit card statements, as PDFs or CSV exports (up to 20 files in one chat)
• Your latest card processing statement
• A Claude account (Free works)
• A pen, or a second screen, for marking what you actually use

Before you upload anything, black out full account numbers. On a personal Claude account (Free, Pro or Max), open Settings > Privacy and find "Help Improve our AI models." Turn it off if you'd rather your chats didn't train future models. Team and Enterprise accounts don't train on your content by default.

As of October 20, 2026, the free plan covers this job. You can attach up to 20 files to one chat, and Claude reads PDFs, CSVs and Excel files. It reads a PDF of 100 pages or fewer in full, pictures and charts included. Past 100 pages, it reads the text only.

Free can also produce a real Excel file to download, instead of only a table on the screen. That takes one setting: Settings > Capabilities > "Code execution and file creation." It's on by default, so confirm that nobody turned it off. The same setting has to be on before Claude will open an Excel file you upload. CSVs work either way.

If your bank offers CSV, take it. The file is smaller than a PDF, and it leaves Claude nothing to misread.

The prompt

Replace the words in [brackets] with your own.

Steps

1. Gather three months of statements and your latest processing statement.
2. Paste the prompt and attach the files.
3. Mark each subscription with the parts you actually use. Be honest: a module you opened once doesn't count.
4. Ask Claude, with the follow-up prompt, to add a last column: keep, cut, replace or build.
5. Check the effective rate against the totals printed on your statement.
6. Download the Excel file from the chat. It stays available for the life of that conversation.
7. Save the table, and set a reminder to redo it every three months.

Check the result

• Every subscription in the table matches a line on a statement.
• The effective rate holds up when you redo the math with a calculator.
• Anything Claude couldn't find says "not shown" instead of a guess.
• You can name at least one thing you're paying for and not using. For me, it was a menu engineering module in our POS: too complicated to set up for what it could save, and my team wasn't ready for it.

How do I read a card processing statement?

Every processor lays out its statement slightly differently. Most still put the two numbers you need near the top, on a summary or cover page.

• Total card sales. It might say total volume, total sales, gross sales or amount submitted. This is what customers paid you on cards before any fees came out.
• Total fees. It might say total fees, fees charged or total discount. This is everything the processor, the card brands and the banks took that month.

Divide total fees by total card sales. The result is your effective rate.

Sample math (made-up numbers). Say you run a small heating and cooling company with two people in the office. Last month's statement shows $62,400 in card sales and $1,716 in total fees. Divide $1,716 by $62,400 and the result is 0.0275, so your effective rate is 2.75%. At that pace for a year, you'd run about $748,800 in card sales and pay $20,592 in fees.

The rest of the statement shows how the processor reached that total. A fee summary breaks the charges out by card brand and type. A deposit section lists each day's batch with the fees already taken out. Some processors take their fees from each deposit, while others take them in one charge the next month. That monthly charge appears on your bank statement, too.

The markup is what you can negotiate. If you're lucky, you'll land interchange-plus pricing, where you pay interchange at cost plus a small markup. That's the ideal, and you'll probably have to press hard to reach it.

If your statement splits sales by card type, compare debit with credit. Debit usually costs you less to accept.

Who your customers are drives that mix. A firm with corporate or high-end clients sees more Amex and other high-rewards cards, and those carry a high rate by nature. A business serving everyday households sees far more debit cards, and its mix will keep changing over the years.

Sample mix (made-up numbers). If $24,960 of the company's $62,400 came in on debit cards, debit is 40% of your card sales and credit is 60%.

On a flat-rate plan, do the math anyway. Say you pay 2.6% plus 15 cents a sale, and your average sale is $12. That sale costs you about 46 cents, which works out to 3.85% of $12. The per-sale fee is the cost people overlook.

What it looks like when it's done

Here's a sample for the same made-up heating and cooling company. Your rows will look different.

Effective card rate: $1,716 ÷ $62,400 = 2.75%. Debit 40%, credit 60%. Per-card-type fees: not shown.

In this sample, subscriptions cost $524 a month. The cut, replace and build rows add up to $230 a month, or $2,760 a year.

Here's what the four calls mean:

• Keep: you use it, and it earns its price.
• Cut: you don't use it, so cancel it.
• Replace: you use a little of it, and something cheaper, or something you already pay for, does the same job.
• Build: you use one small piece, and you can make that piece yourself with Claude, such as a quote template or a simple form.

If it goes wrong

• A scanned PDF comes back blank or garbled. Download the CSV from online banking instead. You can also take a clear screenshot of the summary page and attach it as a picture, since Claude reads JPEG and PNG files.
• The statement is too long. Claude reads every part of a PDF up to 100 pages and only the text from page 101 to page 1,000. It won't accept anything longer. Upload one month per chat, or use CSVs.
• Claude gives a number you can't find. Ask: "Show me the exact line on the statement where you found that number." If it can't point to one, treat the number as a guess. Cross it out and use what's printed.
• You hit the free usage limit. Free has a limit that resets every 5 hours. Split the job into two chats, with subscriptions first and the processing statement second. Turn off web search for this chat, and ask for the Excel file once at the end, because making files uses more of your limit than plain chat.
• There's no download button. Check Settings > Capabilities, and make sure "Code execution and file creation" is on. Failing that, copy the table out of the chat into any spreadsheet.
• A charge has a name you don't recognize. Ask Claude to list unknown charges in their own section. Then search your email for the amount, because that's usually where the receipt went.

Common questions

Can AI read my merchant statement?

Yes, if it's a PDF, a CSV or a clear picture. Claude finds the totals and the fee lines and calculates the rate. It still makes mistakes, so check the two totals by hand.

How do I use AI to find out what I'm really paying in card fees?

Upload your latest processing statement, and ask for total fees divided by total card sales, with the math shown. That number is your effective rate. Compare it with the rate you were quoted when you signed.

Is it safe to upload bank statements to Claude?

Black out full account numbers first. Never upload Social Security numbers or anything else you wouldn't hand a bookkeeper. On Free, Pro and Max, turn off "Help Improve our AI models" under Settings > Privacy so new chats stay out of training. Team and Enterprise don't train on your content by default.

How do I tell which AI tools are wasting my money?

Run them through this same audit. Watch for tools that hook you with five free credits and then start charging, and for subscriptions you don't use.

Go further: the Pro version

Who this is for: you already pay for Claude, your books live in QuickBooks or a similar tool, and you'd rather not download statements every quarter. It's free to read, but running it takes a paid plan.

As of October 20, 2026, here's what the tools do. The Claude for Small Business plugin runs in Cowork, inside the Claude desktop app for Windows or Mac, on Pro, Max, Team and Enterprise.

The plugin can connect to QuickBooks and 36 other business tools. None of its workflows is a subscription audit. The closest are /close-month, which reconciles your books against your payment processors, and /pay-the-bills. You'll still bring the audit prompt from above.

The QuickBooks connector's page covers profit and loss, cash flow, comparisons with similar businesses and importing transactions. It doesn't say the connector reads your vendor list, and it doesn't say which plans include it. Every plugin workflow starts in approval mode, so nothing sends, posts or pays until you say so. If you haven't connected anything, the plugin page says most workflows still run on an uploaded spreadsheet or statement.

1. Install the plugin. Open Cowork, click Customize in the left sidebar, click + under Plugins, find Small Business and click Install.
2. Run /smb-onboard. Type / in the Cowork message box and pick it from the list. It asks about your business and helps you connect tools like QuickBooks.
3. Paste the audit prompt from above, with one change: replace "Attached are my last three months of statements" with "Use my connected accounts for the last three months." Still attach your card processing statement for the rate math. If Claude can't see the charges, attach the CSVs instead.
4. Check every row against QuickBooks or your statements, the same as in the free version. Approve nothing you haven't read.
5. Save it as a recurring job. The plugin's build-agent turns a task you do by hand into a workflow you can run by name or on a schedule. Run it every three months.

If the processing number surprises you, Your business doesn't need an enterprise product explains why your card mix matters.