Over 60s with a bus pass can now travel across the country for free after the government broke down barriers between councils and different bus operators.
Older people already receive free local travel on buses between 09:30 and 23:00 on Monday to Friday and anytime on weekends and bank holidays.
The scheme has now been extended so the pass can be used all over the country, not just in the passenger's own local authority.
But there have been problems with the scheme already.
Several regional newspapers have reported delays to pensioners receiving their 'smart card' bus passes on time.
Difficulties with suppliers mean eligible residents in counties including Cheshire, Norwich and Hampshire have yet to receive their passes.
In addition, not all buses are equipped to read the smart card passes.
A transport select committee report published today criticised the government over the delays.
"The current situation whereby 11 million concessionary travel smartcards have been issued but most buses are not equipped to read them is daft," the report said.
"The government needs to agree a programme with bus operators for installation of ITSO smartcard equipment on buses."