Account
Checking the balance, and keeping it topped up
A short balance is the most common reason a tag fails, and since 2026 it is also one of the most expensive. The fix is dull and it works: keep a buffer and check it before long drives.
Keeping track
Every deduction generates an SMS with the amount and the plaza name, which makes the message log the fastest informal statement you have. Beyond that, the issuing bank's app and the tag's account portal both show the running balance and recent crossings.
SBI's FASTag portal now sits on fastag.sbi.bank.in, under the bank's sbi.bank.in domain. Older guides — including a good many still ranking — point at addresses that have moved. Fake FASTag login pages are common, so reach the portal from the bank's own domain rather than from a search result or a message.
Topping up
Recharge through the issuing bank's app, UPI, net banking or a transfer to the tag account. The money lands in the tag's prepaid wallet, which is separate from your bank balance — that separation is the point, since the toll never reaches your account directly.
How much buffer to hold
More than one crossing. A marginal balance fails in ways that look like a hardware fault, because the reading and the deduction happen in the same second. For regular highway driving, holding several crossings' worth avoids the whole category of problem.
With cash lanes closed, a failed tag means the digital fallback and its convenience charge of roughly 25%, and a tag that tips into blacklisting can be charged double or refused.
If a deduction looks wrong
Compare the SMS against the posted rate for your class at that plaza. Disputes over an incorrect class, a double deduction or a charge at a plaza you did not cross go to the issuing bank, and the SMS log is the evidence that settles them.