I have listened to the tutorial advising me of the steps to change the bank account to pay my monthly subscription however I cannot see anything where this info is stored

Hello, ma-sims-hotmail-.

I'll give steps and screenshots where you can update the billing information for your subscription.

Here's how:

1. Sign in as a master or company admin.
2. Go to the Gear > Account and settings.
3. On the left panel, click the Billing & Subscription tab.
4. Next to your payment method, click the pencil icon.
5. Update your credit card info. Learn more about accepted payment options.
6. Review the address for your credit card. It must be the same one that appears on your credit card statements.
7. Hit Confirm card or Save.

Please see this sample screenshot for a visual reference:

You can also read this article for more information: How to update your subscription and billing details.

To see other video tutorials for QuickBooks Online, you can click on this link: QuickBooks Online Video tutorials.

Please let me know if you're able to update the account information. I'll be right here to help you out again. Have a good day!