This article explains how to cancel your Square account. To do this, you need to contact Square directly at the addresses listed on the app's contact page (available in English only). Despite Square's claims about the deactivation operation, it is not possible to close an account from the dashboard.
Steps
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Step 1. Open Square's contact page
Go to https://www.squareup.com/help/contact using your favorite browser.
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Step 2. Click Account Settings
This item is the first of the "SELECT YOUR TOPIC" section.
If you are not logged in, you will be prompted to do so now, by entering your email and password
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Step 3. Click Deactivate My Account
This is the first option on the next page.
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Step 4. Click I STILL NEED HELP
You will see this entry under the "Deactivate My Account" field.
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Step 5. Click Email Support
It is the first item in the list of options on this page.
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Step 6. Write your account cancellation request (in English)
You can do this in the field below "Tell us a little more about your issue". Make sure you describe your request directly and concisely.
For example, you can write "I would like you to deactivate my account for me"
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Step 7. Click SUBMIT
You will see this button below the email field. Press it and you will send a message to Square's technical support, who will evaluate it and, hopefully, fulfill your request.
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Step 8. Wait for a confirmation email
Once your account has been deactivated, Square's technical support will send you a confirmation message.