It's great to see you here joining this thread, @supplier. 

For me to fully address your concern and provide you with a detailed resolution, may I know what accounts you wish to modify in QuickBooks Online (QBO)? What changes you'll want to make to your accounts? This way, I'll be able to walk you through the process and further provide you with thorough information to help resolve your issue.

Any additional information is much appreciated, as this will help me verify I've got the proper workaround for you.

If you meant modifying your accounts even with the multicurrency turned on, please refer to this article to guide you on how: Set up and use multicurrency in QuickBooks Online.

Feel free to get back to us and leave a reply below for any additional QuickBooks-related concerns. We'd be glad to help you. Keep safe!

There aren't any options for me when selecting A/R, but I do have the option if it's a bank account. What's going on here?

Thanks for joining the thread, @The Carbon Offset Company.

Let me share insights about creating an Accounts Receivable (A/R) account with a different currency in QuickBooks Online.

QuickBooks only allows you to associate different currencies when creating Banks, Other Current Assets, Fixed Assets, Other Assets, Credit Cards, Other Current Liabilities, and Long-Term Liabilities accounts. 

The program will automatically create an A/R account depending on the currency associated with your customer. For example, when you create an invoice for a customer with GBP currency, an A/R account will show on your Chart of Accounts with the same currency.

You might want to group your Accounts Receivable account types. This article will guide you through the steps: How to group Accounts Receivable or Accounts Payable account types.

For additional reference about multicurrency, you can check out these articles:

• How to add transactions in a foreign currency
• Understanding Home currency adjustment

I'm still open to your replies if you have additional questions about multicurrency. Have a good one.