Total minimum contributions had been set to rise from 2% to 5% in October 2017 then 8% in October 2018.
But in today's Autumn Statement, chancellor George Osborne said the government would bring these increases into line with the tax year.
He said:"Over five million people have already been auto-enrolled into a pension thanks to our reforms in the last parliament.
"To help businesses with the administration of this important boost to our nation's savings, we'll align the next two phases of contribution rate increases with the tax years."
The increases will now happen in April 2018 and 2019.
Government documents revealed this would yield £390m in 2017-18 and £450m in 2018-19 as tax relief on contributions wil be lower.
Auto-enrolment was introduced by Labour in the 2008 Pensions Act and implemented by the coalition government in 2012