Can I set an exchange rate fixed for conversion to the home currency?

Hello @9130351772526556,

Welcome to the Community. I can share clarification about adding a fixed exchange rate in QuickBooks Online.

You have the option to set the preferred rate for your currencies in the Online version. In the Currencies section, you can choose Your Rate instead of Market Rate to ensure the conversion will be accurate and based on the information you enter.

Here's how:

1. Click the Gear icon in the upper-right corner.
2. Select Currencies under Lists. 
3. Search for the currency.
4. Click Edit currency exchange.
5. Choose Your rate. 
6. Set your custom exchange rate.
7. Hit Save.

For additional reference, I've attached a link you can visit to learn how to revalue currency or create adjustments in QuickBooks: Enter home currency adjustments for your foreign balances.

Let me know if you need additional assistance with multi-currencies or changing the values. I'll be more than happy to lend a hand.