Change the default currency carefully
The default currency is the base for exchange-rate calculations. Changing it has a broader effect than editing the rate of a secondary currency, so confirm the target currency and intended rate first.
Prepare the change
Open **Settings → Currency & Wallet → Currency**. Confirm the existing default and the rate of the currency that should become the new default. Record the rates you expect to see afterward so you can compare the result.
Set the new default
1. Open the target currency's editor.
2. Review the warning that default-currency changes affect base exchange-rate calculations.
3. Acknowledge that warning to reveal **Make Default Currency**.
4. Enable it and save.
5. Refresh System Currencies and confirm the target is active, marked default, and has rate 1.
What changes
When an existing currency becomes the default, the saved rates of other currencies are rebased using the previous rate of that new default. The default itself is forced active with rate 1. This is not the same as converting every historical invoice or customer balance into a new currency.
Check afterward
Inspect representative prices and currency choices before continuing normal operations. If a save fails, reload and confirm which default is currently stored. Do not try to unset the original default first; select the intended replacement through the supported action.