That's a great question. I know it's important to make sure you're on the plan that works best for you and your budget. Downgrading is a feature that we introduced to QuickBooks Online earlier this year to better help our customers achieve that goal. One of the downgrading limitations, however, is multi-currency. Learn more by reading the downgrading your subscription article.
Once multi-currency is turned on, there isn't a way to turn it off. This is to ensure that transactions made while it was turned on are preserved correctly in the account as the feature draws on the currency exchange from Wall Street on Demand. You can read more about currency using the links below if you'd like to know more.
Creating a brand new account will get you to the QuickBooks Online subscription that you'd like, in this case. You'll be able to export and import some of your data from one account to the other so you don't have to completely re-enter everything. Or you can wait until the end of your fiscal year so that you can tie up loose ends before starting fresh.
Here are a few other articles with more information about what I've mentioned above.
Let me know if you have more questions. Enjoy your day!
It's important to me that you can upload your receipts into your account. QuickBooks Online allows you to easily upload receipts with or without the multicurrency feature turned on. Here's an article to assist you with that: Capture and categorize receipts and bills
If you still need to turn your multicurrency feature off, you'd have to open a new account using the steps shared above on this thread.
Have a nice day!