Mexico City has a vast public transport network consisting of the metro, the Metrobus (a bus rapid transit system), Light rail ( Tren Ligero and Suburbano), trolebus ( trams), and a range of buses.
There are only 2 ways of paying for transport in Mexico city
Smart cards ( Tarjetas)
Transport smart cards
Tarjetas are readable smart cards that are you used to pay for some means of transport within Mexico city. Not all public transport providers accept payment by smart cards currently though the city is aiming for this. As at now, Tarjetas are only accepted on:
The metro- both smart cards and one-time tickets accepted.
The metro bus - You can only pay by the smart card.
Tren Ligero- You can only pay using your smart card
Trolebus- There are 2 types of trams: The regular trams and the blue electric trams. In the blue trams, you can only pay using your smart card. Some of the old trams have also been fitted with card readers, most old trams still accept payment in cash.
How to get a Tarjeta smart card
You can buy a smart card at metro stations, Metrobus stations, and tren Ligero stations. If you can't speak Spanish, it's most convenient if you get the cards at either the metro bus station or Tren Ligero stations. They have self-service machines that sell these smart cards at the Metrobus and Tren Ligero stations. At the metro stations, you have to buy the card from an attendant at the ticket booths. Most of these attendants only speak Spanish.
Smart card cost: 10 pesos. You have to pay in cash when purchasing the card.
Where to recharge your card: Once you place your card on the card readers, your balance is always indicated after fare has been deducted. Recharge ( recargar) can be done at the metro, metro bus and Tren Ligero stations or at 7 eleven stores.
How to pay in Cash
You can't pay directly by cash on the metro, you have to purchase a ticket at the ticket booths. Tickets cost Mex$ 5 regardless of your route. There's a ticket slot at the entry metro turnstiles. Insert your ticket into the slot for you to pass through the turnstile. You won't get the ticket back.
Some turnstiles at the metro are only for tarjetas, they are indicated 'solo tarjeta'.
For bus fare, most buses have a coin box that you can drop your fare into. In case the bus doesn't have a coin box the driver will be collecting fare.
Ensure you have exact cash.
RTP buses, which are the government-run buses, cost Mex$ 2 for regular buses and Mex$4 for express buses.
Private owned buses (Eco bus and Microbuses) charge either Mex $5 for shorter trips and Mex $6 for longer trips.