https://en.wikipedia.org/wiki/Informal_value_transfer_system https://en.wikipedia.org/wiki/Informal_value_transfer_system "The sender gives money to an...agent

https://en.wikipedia.org/wiki/Informal_value_transfer_system https://en.wikipedia.org/wiki/Informal_value_transfer_system "The sender gives money to an...agent and his/her counterpart in the receiver region/country acts as deliverer of this money. The sender calls or faxes instructions to his counterpart and the money gets delivered in a matter of few hours. In the past, the message could be delivered using couriers, with men or even animals (such as pigeons). Settlements are made either with a private delivery service or wire transfer in the opposite direction. Another method of balancing the books is to under-invoice goods shipped abroad, so that the receiver can resell the products at a higher market price"