Free tools & guides

Find errors.
Fix bills.

Free guides and tools to check medical, utility, phone, and insurance bills for errors — and dispute them when you find one.

Browse guides Dispute letter

What bill are you checking?

Pick your bill type for a step-by-step guide on what to look for, how to check the math, and how to dispute errors.

Medical Bills

Hospital bills, doctor visits, dental, pharmacy. Check CPT codes, spot duplicate charges, compare against Medicare rates.

Read guide

Utility Bills

Electricity, gas, water, sewer. Verify meter readings, check rate tiers, catch estimated-read overcharges.

Read guide

Phone & Internet

Cell phone, internet, cable, streaming. Spot cramming, verify plan rates, catch post-cancellation charges.

Read guide

Any Bill

Universal dispute guide. Works for insurance claims, subscriptions, auto repair, contractor bills, and anything else.

Read guide

Your State Rights

Balance billing laws, prompt pay rules, itemized bill rights, and medical debt protections — for all 50 states + DC.

Find your state

All Guides

Browse all our billing guides — from reading itemized medical bills to writing effective dispute letters.

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Free tools

Check your bill, look up codes, and generate dispute letters. Everything runs in your browser — nothing is uploaded.

Bill Math Checker

Enter line items from any bill. We'll check the addition, flag arithmetic errors, and catch duplicate charges.

Any bill type

Dispute Letter Generator

Fill in your details, pick your bill type, and get a professional dispute letter with the right regulatory citations.

Any bill type

NCCI Code Pair Checker

Check any two CPT/HCPCS codes against 190,000+ NCCI edit pairs. Catches bundling violations on medical bills.

Medical

CPT/HCPCS Code Lookup

Look up any medical billing code. See what it means, what Medicare pays, and whether the charge on your bill is reasonable.

Medical

Three steps to fix a billing error

1

Learn what to look for

Read the guide for your bill type. We'll show you the most common errors, what each charge means, and exactly where to look.

2

Check your bill

Use our free tools to verify the math, look up codes, and compare charges. Everything runs in your browser — nothing leaves your device.

3

Dispute the error

Generate a dispute letter with the right regulatory citations. Send it certified mail. Follow up in 30 days.

Questions

BillError covers medical bills (hospital, doctor, dental, pharmacy), utility bills (electricity, gas, water), phone and internet bills, and insurance claims. Our guides walk you through exactly what to look for on each type.
Yes. All guides, tools, and dispute letter templates are 100% free with no signup. BillError is an educational resource — we don't charge for access and we don't collect your billing data.
No. All tools run entirely in your browser. Nothing is uploaded or stored on our servers. Your billing information never leaves your device.
Read our universal dispute guide, then use the dispute letter generator to create a professional letter with the right citations. Send it via certified mail and follow up if you don't hear back in 30 days.
No. BillError provides educational information about billing practices and consumer rights based on published regulations. We are not a law firm, billing service, or insurance company. Always consult a qualified professional for legal, medical, or financial decisions.

Stop overpaying.

Pick the guide for your bill type and start checking. It takes five minutes and could save you hundreds.

Browse guides Generate dispute letter