Settings → Currency lets a Group Admin set the default billing currency for the operator account.
Choose one code and select Save Currency. The current list contains BDT, USD, INR, PKR, NPR, KES, EUR, GBP, AED, MYR, PHP, and NGN. ISPbills stores the uppercase code and uses it when resolving the operator’s default currency in billing displays and newly created records that do not carry their own currency.
Changing the default does not convert monetary amounts, apply an exchange rate, or rewrite the currency already stored on historical records. Reconcile existing packages, gateway settings, invoices, and reports before changing a live account.
If a screen still shows an earlier currency, check whether that record has its own saved currency. Confirm a new test bill and payment before continuing normal billing.