You can absolutely purchase gold on your pre-paid phone.
However, pre-paid phones are not eligible for purchasing Moco Gold with their phone bill (through text).
We support the following carriers with payment options for their pre-paid customers:
Users with pre-paid phones on carriers not listed above will not be able to purchase Moco Gold via Text or Mobile Bill payments. Your best option would be to pay by credit/debit card.
Please see the rest of our Moco Gold help section for other alternative payment options.