Quick overview

Billing errors are incorrect charges, duplicate bills, or unauthorized transactions that appear on a credit card, utility, medical, or other invoices. Acting quickly and following a written, documented dispute process gives you the best chance to reverse the charge and protect your credit history. The steps below explain what to collect, what to write, how and when to send your letter, plus a ready-to-use dispute letter template.

Why the written dispute matters

A phone call can be useful for quick clarifications, but a formal written dispute creates a legal record and triggers protections under consumer law — most notably the Fair Credit Billing Act (FCBA) for open-end (credit card) accounts. Under that law your creditor must acknowledge your written dispute within 30 days and complete the investigation within a reasonable period (commonly up to 90 days) (see CFPB: Disputing credit card billing errors). For disputes involving bank transfers or ATM/debit errors, different rules under the Electronic Fund Transfer Act (Reg E) apply — treat those claims as time-sensitive and contact your bank immediately (see CFPB: Errors on your bank account). (CFPB: https://www.consumerfinance.gov/; FTC: https://www.ftc.gov/)

Step-by-step process

  1. Confirm the error
  • Compare the charge to receipts, contracts, and prior statements. Note the date, merchant name, amount, and why it’s incorrect (duplicate, wrong amount, canceled service billed, unauthorized charge).
  1. Gather supporting documentation
  • Print or save a copy of the statement with the error circled.
  • Collect receipts, cancellation confirmations, emails, proof of return, and any prior billing that shows the charge is incorrect.
  • Create a simple evidence list so you can attach copies to the dispute letter.
  1. Know the deadlines
  • For credit card accounts covered by the FCBA you typically must submit a written dispute within 60 days of the statement date that first showed the error. The creditor then must acknowledge receipt within 30 days and resolve the dispute within a reasonable time (commonly 90 days) (CFPB guidance). Different timeframes apply to bank accounts and other payment types—act promptly.
  1. Draft the dispute letter (use the template below)
  • Be concise and factual. Include account number, the exact amount in dispute, the date of the charge, and a short explanation of why it’s incorrect.
  • List the documents you are attaching as evidence.
  • State your requested remedy (credit, reversal, corrected statement) and reference the FCBA if it’s a credit-card dispute.
  1. Send the letter the right way
  • Mail the letter by certified mail with return receipt requested or send via a trackable courier. For many creditors the provider also accepts secure online forms, but keep a copy of any submission confirmation.
  • Keep copies of everything you send.
  1. Track the creditor’s response
  • Note the date the creditor acknowledges receipt (they must within 30 days for FCBA disputes). If they don’t respond in their required window, follow escalation steps below.
  • Continue to pay any undisputed balance and any portion of the bill not under dispute. You may withhold payment for the disputed portion while the creditor investigates under the FCBA, but do not stop paying amounts you acknowledge as valid (CFPB).
  1. Follow up and escalate if needed
  • If the creditor’s answer is unsatisfactory or they ignore you, file a complaint with the Consumer Financial Protection Bureau (CFPB) and consider contacting your state attorney general or local consumer protection office. FinHelp’s guide on how to escalate a dispute walks through the evidence you’ll want to include. (See internal resource: How to Escalate a Billing Dispute with Your Bank: https://finhelp.io/glossary/how-to-escalate-a-billing-dispute-with-your-bank/)

Dispute letter template (fill in the brackets)

[Your name]
[Your address]
[City, State ZIP]
[Phone] [Email]
[Date]

Billing Department
[Creditor / Company Name]
[Creditor Address]

Re: Account number: [last 4 digits or full account number per issuer guidelines]

To whom it may concern:

I am writing to dispute a billing error on the account referenced above. The statement dated [statement date] includes a charge of [amount] posted on [date posted] to [merchant name / service description] that is incorrect because [concise reason: duplicate charge / canceled service / unauthorized / incorrect amount].

I request that you investigate this charge, remove it from my account, and correct any fees or interest that resulted from it. I have enclosed copies of supporting documents: [list attachments, e.g., receipt, cancellation confirmation, prior statement].

This dispute is submitted under the Fair Credit Billing Act (if applicable). Please acknowledge receipt of this letter in writing within the time period required and advise me of the result of your investigation.

Sincerely,

[Your name]

Attachments: [list documents]

Notes on the template

  • Use clear labels for attached documents and include page numbers, if helpful.
  • If the dispute involves an unauthorized or fraudulent charge, also contact the card issuer’s fraud department and consider filing a police report for identity theft.

Sample follow-up phone/email script

If you call: “Hello, my name is [X]. I sent a written dispute on [date] about account [last 4 digits]. I’m calling to confirm you received it and to ask when I can expect an acknowledgement and resolution.” Record the name of the representative and the date/time.

If you email: Keep the subject line exact and professional, e.g., “Billing dispute: account [last 4 digits] — [your last name]” and attach the same documents you mailed.

Evidence checklist to include with your letter

  • Copy of the statement with the error circled
  • Receipt or proof of payment/return
  • Cancellation confirmation, if applicable
  • Screenshots or email exchanges with the merchant
  • Prior statements showing correct balances
  • Any correspondence showing merchant error or refund promise

Common mistakes to avoid

  • Waiting too long: Missing the 60‑day window for FCBA claims can limit your legal protections.
  • Sending only verbal complaints: Phone calls are useful, but they rarely substitute for a written notice.
  • Not keeping copies: Without records you’ll have a harder time proving the error.
  • Overlooking bank-specific rules: Debit card and ACH disputes follow different regulations—reach out to your bank’s dispute unit immediately for those claims.

If the creditor refuses to correct the error

  1. Escalate internally: Ask to speak with a supervisor or the billing department manager.
  2. File a complaint: Submit a complaint to the CFPB (https://www.consumerfinance.gov/) and include copies of your letters and proof of delivery. FinHelp’s guide on when to file a complaint explains what evidence helps most (see: When to File a Complaint with the CFPB: https://finhelp.io/glossary/when-to-file-a-complaint-step-by-step-with-evidence/).
  3. Consider legal remedies: If the amount is significant and you have strong documentation, consult an attorney about small claims or consumer-protection lawsuits. Your state’s attorney general may also accept consumer complaints.

Timeline summary

  • You discover the error: Day 0 — collect evidence immediately.
  • Send written dispute: Within 60 days of the statement date (for FCBA credit-card disputes).
  • Creditor acknowledges: Within 30 days (FCBA).
  • Creditor completes investigation: Usually within 90 days; they must correct the error or explain in writing.
  • If unresolved: File CFPB complaint and escalate to state consumer protection.

When to get professional help

In my practice I recommend consulting a consumer-protection attorney if:

  • The disputed sum is large and the creditor refuses to correct it.
  • The creditor reports negative information to the credit bureaus despite your dispute.
  • You suspect identity theft or coordinated fraud.

Useful authoritative resources

Final notes and disclaimer

This guide explains the common legal timelines and a practical letter template that I’ve used successfully with clients. It is educational in nature and does not replace legal advice tailored to your situation—if you need personalized counsel, contact a licensed attorney or a qualified consumer counselor.

If you’d like, I can customize the template for a specific charge type (medical, utility, credit card) or review a draft of your letter and suggest edits.