Wikipedia
Boleto
Boleto Bancário, simply referred to as Boleto ( English: Ticket) is a payment method in Brazil regulated by FEBRABAN, short for Brazilian Federation of Banks.
A boleto can be paid at ATMs, branch facilities and internet banking of any Bank, Post Office, Lottery Agent and some supermarkets until its due date. After the due date it can only be paid at the issuer bank facilities.
Boleto can only be collected by an authorized Collector Agent in the Brazilian territory. All Brazilian banks, Post Offices ( Correios) and Lottery Agencies plus some companies from the private sector have joined the system.
Open source projects like BoletoPHP allow the merchandisers to generate unregistered Boleto Bancários without communicating with the bank.