My bill went up. What changed?

A bill arrives higher than last month, and the reason is buried somewhere across three pages of line items, taxes, fees, and a promotional credit that may or may not have ended. You don’t need to decode all of it. You need to know what changed and what to ask.

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Before you paste anything

Bills carry details AI doesn’t need: your name, address, account number, and sometimes part of a payment card number. Take them out first. Keep the line items, amounts, dates, and plan names, because those are what the comparison is about.

If your bill is a PDF or a photo, you don’t have to share the whole page. Type out only the charges, or capture a picture of that part alone:

What should I never share with AI? walks through a made-up bill with the personal details removed.

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Do this

1. Copy the charges from both bills into a note: every line item and amount, plus the billing period dates. Leave out the identifying details.
2. Paste both into any AI chat app, clearly labeled as the old bill and the new bill.
3. Ask for a line-by-line comparison, using the prompt below.
4. Check each change it lists against the actual bills. It’s reading text, and it can misread a line.
5. Contact the company with the questions, not the whole comparison.

Here are the charges from two bills from the same company.

OLD BILL (billing period [dates]):
[paste charges and amounts]

NEW BILL (billing period [dates]):
[paste charges and amounts]

1. Make a table: each charge, old amount, new amount, and the
   difference.
2. List anything that appears on one bill but not the other.
3. Add up the changes. If they don't match the difference between
   the two totals, say so.
4. Write three or four short questions I could ask the company.

Only use what's in these two bills. Don't guess at reasons the
bills don't state.

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Check this before you trust it

• Every amount in the table, against the bills. One misread number makes the whole comparison wrong.
• Whether the changes add up. If it says the changes explain a $22 increase, add them yourself.
• Any reason it gives for a change. Unless the bill says why (a rate change, an ended discount, a new fee), the reason is a guess.

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If it goes wrong

The billing periods are different lengths. A 35-day bill and a 28-day bill will differ even if nothing else changed. Tell it the number of days in each and ask it to compare the cost per day too.

It explains a charge confidently, and the bill doesn’t say that. Treat the explanation as a question to ask the company, not an answer. Fees and rates vary by company and location, and it can’t see your account.

The bill uses terms you don’t recognize. Ask: “What does [TERM] usually mean on a bill like this?” Then confirm with the company, because the same term can mean different things on different bills.

The company’s answer doesn’t match the comparison. Ask them to point to the specific line on the bill, and write down what they tell you.