Cancel your Flex subscription by mail
For Flex the route is a written letter: cancellation requests are taken by post, and certified mail shows when yours arrived. Post for Flex is handled in Miami, United States, which is where your letter is headed.
Let Postbye cancel Flex for you
We write your letter, mail it by certified mail the next business day, and confirm when the cancellation went through. You keep the signed proof.
Money-back guarantee within 10 business days.
Postbye is not affiliated with Flex.
- 4.8 from 2,931 reviews
- 2 Flex cancellations handled this month
- Certified mail with tracking
- Mailed every business day
- Delivery proof sent to you
- We confirm your cancellation
How to cancel Flex by mail
Note your account details
Check the name and email on the account and, if you have one, an account or customer number before anything else. A request that does not match the account on file at Flex is the easiest one to set aside.
Set out the request
The letter asks Flex to end the account, stop every future charge and confirm it in writing, under the subject line “Subject: Subscription termination – Flex”. Postbye fills it in from our English template.
Mail the letter with a receipt
Take the letter to the post office and ask for certified delivery to 33179 Miami. Keep the tracking number it gives you.
Keep proof the letter arrived
Delivery confirmation is your evidence that Flex was asked. Watch the next statement or two for any further Flex charge.
With Postbye, steps 2 to 4 take about two minutes of your time.
Where your Flex cancellation letter goes
Written requests to Flex go to Northeast 191st Street 390, 8019, Miami 33179.
ZIP code 33179 places the address in Florida, in the United States.
Inside, the salutation reads “To Whom It May Concern,”, followed by your details under Name, Address and E-mail.
Prefer to write it yourself? Use our letter template
Before you cancel Flex, check these
- Look for annual or multi-month plans. A plan paid in advance usually runs to the end of the period you paid for.
- Write well before the next billing date. A request that arrives after it can leave one more charge on your statement.
- If an app store or phone carrier bills you, the company cannot cancel it. Cancel with that partner as well.
Several states set rules for subscriptions that renew on their own. See what yours requires in automatic renewal laws by state.
Let Postbye cancel Flex for you
We write your letter, mail it by certified mail the next business day, and confirm when the cancellation went through. You keep the signed proof.
How cancelling by mail works
A subscription ends when the company records your request, not when you stop using it, and a letter is the record you can show later.
A phone call leaves nothing behind; a letter leaves a copy, a date and a delivery receipt.
Flex cancellation at a glance
- How Flex accepts cancellations
- By mailed letter
- Mailing address on file
- Flex Northeast 191st Street 390 8019 Miami 33179
- Country
- United States
- Letter language
- English (template en)
- Added to the database
- May 19, 2026
- Data last checked
