Cancel your Stackup subscription by mail
Stackup takes cancellation requests by mailed letter, so a dated certified-mail letter is the record that counts. Post for Stackup is handled in Toronto, Canada, which is where your letter is headed.
Let Postbye cancel Stackup 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 Stackup.
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- 2 Stackup cancellations handled this month
- Certified mail with tracking
- Mailed every business day
- Delivery proof sent to you
- We confirm your cancellation
How to cancel Stackup by mail
Start with your account details
Start with the name and email on the account and, if you have one, an account or customer number, so the request to Stackup names the right account the first time.
Prepare the letter
Postbye turns the request into a finished English letter headed “Subject: Cancellation Request – [your name]”: close the Stackup account, stop every charge and reply in writing.
Post the letter
Address the envelope to Stackup, Toronto, exactly as printed in the next section. Certified mail gives you a tracking number and a delivery record.
Keep the delivery receipt
Once the letter is delivered, the date on the receipt is the date Stackup was told. Compare it with your statements over the next billing cycle.
With Postbye, steps 2 to 4 take about two minutes of your time.
Where your Stackup cancellation letter goes
The mailing address we hold for Stackup is Atlantic Avenue 60, M6K 1X9 Toronto, Canada.
Copy the postal code M6K 1X9 exactly: it is what routes the letter to Ontario, Canada.
Your details go in a block headed by Account holder, Billing address on file and Email on file, and the opening line is “To Whom It May Concern,”.
Prefer to write it yourself? Use our letter template
Every address we hold for Stackup, with the envelope wording
Before you cancel Stackup, check these
- 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.
- Cancelling usually ends access at the end of the period you paid for, so you keep what you paid for until then.
Several states set rules for subscriptions that renew on their own. See what yours requires in automatic renewal laws by state.
Let Postbye cancel Stackup 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
Most subscriptions keep billing until someone tells the company to stop, and a dated letter is proof that somebody did.
Putting the request in writing means there is a date on file for when you asked, which matters if a charge appears afterwards.
Stackup cancellation at a glance
- How Stackup accepts cancellations
- By mailed letter
- Mailing address on file
- Stackup Atlantic Avenue 60 M6K 1X9 Toronto Canada
- Country
- Canada
- Letter language
- English (template en-generic)
- Added to the database
- May 19, 2026
- Data last checked
