Victoria's Myki has hit another snag, with its website frustrating commuters who are unable to check their account balances or histories.

Registered Myki cardholders can usually monitor when and where they have touched on and off and how much they have spent each day through the myki website.

But the transaction history tool stopped working four days ago and is yet to come back online.

Public Transport Users Association president Daniel Bowen said commuters could usually check if they had been charged correctly or if they needed to top up their pre-paid accounts.

"If it's not updated for days at a time, it's a lot more difficult to manage your account," he said.