You can dispute a free trial charge in writing with cancellation proof and a notice to your card issuer if the seller keeps the money. That path is ordinary U.S. consumer process.

Already billed after you cancelled?

Start with the merchant, then put the same facts in a billing dispute with your card issuer if the money is still gone. Tone matters less than dates.

Credit card billing-error rights in the United States rest on federal rules, not on whether the company likes your wording.

What actually controls a free trial dispute

The refund button on a trial page is company policy. A "yes" there depends on that business, not on a special court form.

Thing is, a merchant refund and a card dispute can run at the same time. You do not have to pick only one.

Your credit card billing-error process is a legal track. Under the Fair Credit Billing Act, as applied in Regulation Z section 1026.13, you can give written notice that a charge is unauthorized or is the wrong amount. You can also say it is not the transaction you made. The issuer then has fixed time limits to investigate.

People call that a chargeback. Banks often use card-network chargeback tools to handle the same claim. The written billing-error clock still starts from the statement that first showed the charge.

Debit cards and bank withdrawals are not Fair Credit Billing Act cases. The FTC still says to dispute the charge with your credit or debit card company right away if you were billed without consent and the company will not refund you. Ask the bank which process it is using. Don't paste credit-card statute language onto a debit pull unless that bank tells you it applies.

Online trial sellers also have to disclose material terms and get informed consent under the Restore Online Shoppers' Confidence Act. That is a seller duty. It does not, by itself, cut a refund check.

Sample letters you can copy

Use two short letters. One goes to the company. One goes to the issuer if the charge stays.

Merchant version first. Ask for a refund and written cancellation. Attach proof. Keep a copy.

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

[Company name]
[Billing or cancellations address]

Re: Refund and cancellation for [product or trial name], account or order [ID]

I am writing about a charge of $[amount] on [date] for [merchant descriptor on the statement].

I signed up for a free trial of [product]. I cancelled on [date] by [app, email, chat, or phone]. I did not authorize a paid subscription.

Please refund $[amount] to the card ending in [last four digits] and confirm in writing that the subscription is cancelled and will not bill again.

I am enclosing my cancellation confirmation and the statement line. I still have the trial terms I was shown, if they are in my email.

Sincerely,
[Your name]

If you still have an in-app cancel button, use it and screenshot the result. Mail is slower. A paper trail helps when the chat transcript disappears.

For the card issuer, stay close to the FTC sample letter for disputing credit and debit card charges. Send it to the billing-inquiries address on your statement. That is not the same as the payment address.

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

[Card issuer name]
Billing Inquiries
[Address from your statement]

Re: Billing error notice, account [account number]

I am writing to dispute a charge of $[amount] to my [credit or debit] card account on [date of the charge].

The merchant appears as [descriptor]. This was billed as a paid conversion from a free trial of [product]. I did not authorize that paid charge. I cancelled on [date] by [method].

Please correct the error on my account promptly. I request a refund of $[amount]. If your process allows it, please also block later charges from this merchant.

Enclosures: a statement copy and my cancellation confirmation.

Sincerely,
[Your name]

Call the number on the card too. Written notice is what starts the Regulation Z clock on a credit account.

Keep copies. Keep the originals too, and keep a photo of the envelope or the portal confirmation, because copies are what you mail and originals are what you still have if the first packet vanishes.

Deadlines and the packet you should attach

Your credit card issuer should acknowledge a written billing-error notice within 30 days unless it already fixed the bill. Then the investigation clock starts running. It has two billing cycles, and not more than 90 days, to correct the error or explain why it says the charge is valid.

The issuer should not treat the disputed amount as delinquent while that investigation runs. Unrelated charges are still yours to pay.

Miss the 60-day window and you may lose the right to force that investigation. You can still ask the merchant and the bank, but the statutory lever is weaker.

How to send the letter without making extra work

1. Save the statement line, trial emails, and cancel screens. Photograph the phone if that is the only copy.
2. Send the merchant letter if you can find a contact path. Write down that date.
3. Fill the issuer letter with the same dates and amounts. Use the billing-inquiries address.
4. Mail copies, not originals. Certified mail gives you a receipt. A secure portal upload can work if you download the confirmation.
5. Watch for the 30-day acknowledgment on a credit card. Call if it never arrives.

Turns out the evidence pile is usually uglier than the letter. A blurry cancel email still beats a long speech about how unfair the signup felt.

One more practical mess is that some trials run through an app store, a free-gift checkout, or a third-party biller, so the name on the statement will not match the brand you remember, and you can burn a whole evening hunting that descriptor before any letter goes out.

If they refuse the refund

Read the denial first. Their reason should match something in your proof, or the denial is thin.

If they say you never cancelled, resend the confirmation and the date. If they say the terms allowed the charge, describe the cancel steps you actually used. Then send both letters back to the issuer.

An appeal is another short note that restates the amount and the date. Attach the denial and the same proof, then ask them to finish the investigation.

A complaint about the seller can go to the FTC through the same free trial guidance page. That complaint is a record. It does not replace the billing-error notice.

Limits, then the next thing to do

A letter will not unwind a trial you clearly accepted and then used after the free window without cancelling. Authorized renewals with clear terms are harder to reverse. Charges you never agreed to, or bills that arrived after a real cancel request, are the stronger facts.

It also cannot force a debit-card bank to use credit-card Fair Credit Billing Act deadlines.

To be honest, a $40 fitness trial rarely belongs in small claims court if you still have time to file the card dispute with proof.

Open tonight's statement and circle the charge. If it is a credit card and you are still inside 60 days of that statement, get the billing-inquiries letter out this week.