The SUBE card's negative balance system allows travel even when the card has insufficient funds. Additionally, in Buenos Aires subway and several bus lines, it is now possible to pay with bank cards and virtual wallets, a useful alternative if the negative balance limit is exhausted. Those who wish to check their balance can do so on the official website (Mi SUBE), the SUBE app, or by tapping the card on an NFC-enabled phone. This means that even with a zero balance, travel is possible as long as the fare amount does not exceed this limit. The SUBE card can be used on buses, trains, subways, and premetro. In these cases, the system allows a differentiated negative balance depending on the line. To avoid issues, it is recommended to register the SUBE card, as this guarantees access to benefits and facilitates the management of top-ups and inquiries. The maximum balance a SUBE card can hold is 40,000 pesos, and electronic top-ups are credited via the app, 'Carga a Bordo' on buses, or Automatic Terminals. On trains in the Buenos Aires Metropolitan Area (AMBA), the margin is lower and varies by line. This function is active throughout the country where the network operates and is key in a context of higher fares, especially outside AMBA. With the increases applied at the beginning of 2026, the 'emergency' margin becomes more relevant: if the fare value is within the allowed limit, the trip is validated normally and the deduction is pending for the next top-up. According to Agencia Noticias Argentinas, on buses nationwide and in the Buenos Aires subway, the maximum allowed negative balance is -1,200 pesos, according to official system information.
