To inform us of which currency you are accepting payment in, you should send us a currency code for the appropriate currency from the ISO 4217 list in the $currency_code field.

If you're accepting payment in Bitcoin, send the currency code BTC. If you are accepting payments in points or an internal currency, you should set $payment_type to $points and convert $amount to the monetary value of the points (if possible), setting the currency code to the local currency.

The $currency_code field is not case sensitive, but we suggest sending the codes in all capital letters.