Telecom invoice audit: how to check a carrier bill line by line

A telecom invoice audit means reading every charge line on a carrier invoice and asking whether you should be paying it. Four questions find most of what is wrong: is the service still billing after you disconnected it, did a rate change since last month, is a line on the bill twice, and is a one-time charge repeating.

This guide shows how to do that by hand, with a worked example, and where a script or a tool does the reading for you. The same method applies whether you call it a telecom bill audit or a telecom billing audit.

What do you check on a carrier invoice, line by line?

You check each line against two things you already have: last month's invoice and your own record of what you disconnected. Everything on the bill is a line with a service ID (a circuit ID, phone number or line identifier), a description, a period and an amount. Four checks cover them:

• Billed after disconnect. A recurring charge whose service ID is on your disconnect list and whose billing period ends after the disconnect date.
• Rate change. The same service ID and the same charge description, billed last month at a different rate.
• Duplicate. Two lines with the same service ID, description, period and amount, on one invoice or across two invoices from the same carrier and month.
• Repeated one-time charge. An install fee, a reconnect fee or a credit reversal that shows up in two months in a row with the same service ID and amount.

A fifth thing is worth a glance but is not a dispute: a new recurring service ID that was not on last month's bill and is not on your disconnect list. It may be something you ordered. If it is not, it belongs on the list too.

What do you need before you start?

You need three files, and the audit is only as good as they are.

1. This month's invoice as a line-item export. Most carriers offer a PDF and many offer a CSV or Excel export of the line detail. The export is much easier to work with because each line is already a row.
2. Last month's invoice in the same format, so you can compare rate for rate.
3. A disconnect list. Service ID and disconnect date, one row each. This is your own record: no invoice can tell you what you meant to cancel. If you do not have one, rebuild it from your cancellation confirmations and ticket history, and keep it up to date from now on.

How do you do the audit by hand in a spreadsheet?

Put each month's lines in one sheet with these columns: service ID, description, charge type, period from, period to, quantity, rate, amount. Then:

1. Clean the service IDs. The same circuit can print as 51.HCGS.123456..TWCC on one bill and 51HCGS123456TWCC on another. Uppercase everything and strip spaces, dots and dashes. For phone numbers, drop a leading country code. Compare the cleaned IDs, never the printed ones.
2. Disconnects. Look up each cleaned service ID against the disconnect list. A recurring line whose period starts before the disconnect date is partly legitimate, because the carrier may prorate the last month, so count the days after the disconnect date. A line whose period starts after the date is billed in full against a service you cancelled.
3. Rates. Match last month's lines to this month's on service ID and description. Subtract. Decide a threshold below which you do not care; a few cents on a mobile line is noise. Write down the old rate, the new rate and the yearly difference (monthly difference times 12) so the number you take to the carrier is the one that matters.
4. Duplicates. Sort by service ID, description, period and amount. Two identical rows next to each other are the signal.
5. One-time charges. Filter the charge type to non-recurring and look for the same service ID and amount in consecutive months.

What does a worked example look like?

Take a fictional company with two months of invoices from one wireline carrier, about 60 lines in each: circuits, SIP trunks, mobile lines, taxes and fees, plus a disconnect list of three circuits. Run the four checks and three things come out:

Note what the rate-change finding does and does not say. It says the rate changed. It does not say the new rate is wrong: that depends on your contract, which a line-by-line check does not read.

What do you do with the findings?

Write one dispute note per carrier. Each entry names the account, the invoice number, the service ID, the line, the amount and the reason. Send it through whatever dispute channel the carrier gives you, keep the date you sent it, and record each finding as disputed, credited or dismissed so next month you do not argue the same thing twice. A rate you accepted at a specific price should not be flagged again at that price.

Where is the time going, and what can be automated?

Reading rows is the slow part. ITG Group's guide to telecom expense management puts disciplined spreadsheet review of a smaller company's bills at 4-6 hours a month, and a case study from Aseva describes about 30 hours a month of accounts-payable reconciliation of carrier PDFs by hand. The checks above are mechanical, which is why they can be run by code rather than by eye.

How Carrier Bill Check does it

Carrier Bill Check runs these four checks, plus the new-line note, on the invoices you upload each month: PDF, Excel or CSV, from any carrier, as long as each line has a service ID, a description and an amount. You confirm the column mapping once per carrier, review the lines it read, and it checks them against your disconnect list and last month's bill. You get the findings with the dollars at stake, a CSV of the open ones and a plain-text dispute note per carrier. It never contacts a carrier. The first month for a carrier has no earlier bill, so only the disconnect and duplicate checks run that month.

You can try it before you sign up on the free run: the sample runs the real checks on two sample invoices, and you can upload one invoice as CSV or Excel to see its lines and any duplicates. For a first pass over a whole account see the telecom audit guide, and for the monthly routine see telecom expense audit.

Frequently asked questions

Does a telecom invoice audit check my contract rates?

No. A line-by-line audit compares each line with last month's bill and with your disconnect list, so it shows what changed, not whether the new rate breaks your contract. To check contract rates you need the contract's rate card, which is a separate exercise.

How often should I audit carrier invoices?

Every month, as each invoice arrives. A charge billed after a disconnect repeats on every bill until someone notices, so the later you find it, the more months there are to dispute, and carriers can limit how far back they will credit. Check your carrier's terms for the window.

What about scanned PDF invoices?

A scanned PDF has no text to read, so you would type its lines by hand. Text PDFs, Excel and CSV exports are far easier to audit, and most carriers offer at least one of them.