I would like to downgrade my subscription as all my multicurrency transactions now go through one bank account.

Hi admin,

Thanks for posting in the Community!

Let me guide you on how to downgrade your subscription in QuickBooks Online. Here's how to:

1. Click on the Settings icon.
2. Click on Subscription & Billing.
3. Click on the QuickBooks plan and click on Downgrade your plan.
4. Select the version you wanted to downgrade to and follow the onscreen prompts.

Just a heads up that if you have turned on the multicurrency in your QBO file you're unable to downgrade the account. You will have to cancel the subscription and sign up for a new one. However, if the current currency in your QBO file is correct, you can leave the account as it is and continue using it since your reports for income and expenses will still be based in your home currency.

If on the event you will cancel the subscription, you can still access the data on file 1 year from the cancellation date. So be sure to export the reports and list for back up purposes. To export reports and list click on Settings icon and click on Export Data.

You can also check this link to learn more about how to cancel your QBO subscription. 

Drop by again in the Community if you have further concerns about your QBO subscription.