The £11.7bn project will start in the autumn of 2015, rather than the summer of next year, the Department of Energy and Climate Change (DECC) said.
It said that the industry needed more time to design, build and test the communications system required.
The devices show exactly how much gas and electricity is being used.
This should bring an end to estimated bills, because the technology could send back an accurate meter reading to an energy company every day.
According to the industry, the technological advance would be the equivalent of using wireless broadband instead of sending a telegram.
The project is considered vital in attempts to cut energy use by households as the UK faces having to import more energy in the future.
The smart meter rollout has been criticised in the past, but the then energy minister, Charles Hendry, said last January: “The last thing we need is more dither and delay.”
With energy prices one of the top financial concerns for consumers, the government must also make sure the £11bn cost does not spiral out of control”
Richard LloydExecutive director, Which?
Now, the programme to install these meters into every UK home is expected to be finished by 2020, also a year later than planned.
Ann Robinson, of price comparison website Uswitch.com, said she was disappointed because smart meters would have “huge benefits”, but added that it was “more important to get it right so that it works for consumers”.
Angela Knight, chief executive of Energy UK, which represents the major energy companies, said: “We welcome the government’s prudent decision to allow an additional 12 months to complete the smart meter programme. This recognises the scale of the programme and the need to prepare carefully.”
She said the installation of meters was a complex task and the delay allowed this to take place “in a more efficient and cost-effective manner, and to greater effect”.
Energy Secretary Ed Davey said: “Completing the national rollout will be an enormous logistical and technical challenge for the industry. Getting this right for consumers is the government’s priority.”
Adam Scorer, of watchdog Consumer Futures, said: “Delaying the date for the smart meter roll-out is a sensible move. The programme is not ready. It will cost consumers around £11bn and unless it goes through a hard and rigorous test it could just mean more costs and fewer benefits for consumers.”
Richard Lloyd, executive director of Which?, said: “The government is right to take its time to ensure the installation of smart meters in every home is a success but it should use this delay to trial regional roll-outs, similar to the digital TV switchover.
“With energy prices one of the top financial concerns for consumers, the government must also make sure the £11bn cost does not spiral out of control.”
Last year, MPs on the Commons Public Accounts Committee said it was “far from certain” consumers would benefit from smart meter savings and urged ministers to oversee the rollout more closely.