More than six million workers have started saving into a workplace pension as a result of automatic enrolment, according to the Pensions Regulator (TPR).
The regulator added more than 100,000 employers have enrolled their staff into the scheme.
Auto-enrolment began rolling out with larger employers in 2012. TPR said thousands of small and micro employers such as scaffolding firms, children's nurseries, farmers, charities and car dealerships, have now also begun paying into workplace pensions for their staff.
Pensions minister Ros Altmann said: "It is brilliant to see so many millions of people automatically enrolling into a workplace pension. So far it has been those working for big firms, now the challenge is to make sure small employers set up pensions too, so their employees get to enjoy this major financial benefit.
"Our pensions reforms are starting a culture of saving which is making pension provision the norm across the UK."
The policy is automatic for staff but hundreds and thousands of small and micro employers need to ensure workers are enrolled into the scheme in the next coming two years, said the regulator.
TPR also warned employers needed to plan ahead to avoid the risk of non-compliance and a possible fine.
Charles Counsell, director of automatic enrolment at TPR, said: "The roll out of automatic enrolment has proved successful so far, with more than 90% of the first small employers required to put their staff into a workplace pension now complying with the law.
"We are finding a minority of small employers are leaving preparations too late. Don't get caught out - use our website to nominate a contact. This only takes around five minutes and means we can contact you with all you need to know to get ready."