Europe
Bus payment guides in Portugal
Portugal's island networks pair cash-on-board with reloadable smart cards. On Madeira the unified SIGA/GIRO card is cheaper than cash, but you can't buy it from the driver.
Lisbon
Lisbon Carris buses sell onboard tickets and Carris lists bank-card onboard payment; Metro Lisboa separately accepts contactless bank cards at the gates. A Navegante occasional card is still usually better for repeat trips.
Read the payment guidePorto
Porto STCP says the entire bus network accepts contactless bank-card payment for onboard tickets; Andante remains the integrated card/ticket system for metro, bus and rail products.
Read the payment guideFunchal
On Funchal's Horários do Funchal / SIGA buses you pay the driver in cash or tap a pre-loaded GIRO card — contactless bank cards, Apple Pay and Google Pay are not accepted on board. Cash is the priciest option (≈€2 urban vs €1.45 on GIRO), and you can't buy or top up a GIRO card from the driver.
Read the payment guide