The Pensions Regulator's inspection team has visited dozens of businesses in and around Manchester to check that qualifying staff are being given the workplace pensions they are entitled to.
The move is part of a nationwide enforcement campaign which began in London to ensure employers are meeting their auto- enrolment duties correctly.
Visits will begin in other towns and cities across the UK in the following weeks.
More than 500,000 employers across the UK have met their auto-enrolment duties, with nearly eight million workers given workplace pensions as a result
The checks will also help The Pensions Regulator understand whether employers are facing any unnecessary challenges that the watchdog can help them with.
But they will also highlight employers who have not taken the required steps to become or remain compliant, paving the way for enforcement action.
The regulator’s most recent quarterly automatic enrolment compliance and enforcement bulletin showed in the first three months of 2017, the watchdog issued a total of 4,673 fixed penalty notices and 1,043 escalating penalty notices.
Darren Ryder, The Pensions Regulator's acting director of automatic enrolment, said: "The vast majority of employers become compliant ahead of their deadline but visits help us to identify why some have not, so we can take action where we need to.
"Every employer has workplace pension duties and we are determined that every worker gets the pension they are entitled to.
"Automatic enrolment is not an option, it is the law. Where we find employers are not complying with the law, we will use our powers to make them comply."
Andrew Cheseldine, partner at Lane Clark & Peacock, said: “This is a two pronged initiative. It can be characterised as enforcement, ensuring that all employers are competing on a level playing field.
“It is also an opportunity for the regulator to understand the day-to-day problems that employers, particularly smaller employers, face when getting involved in a potentially complex area that is often very new for them and it is good to see the regulator showing that they are not only focused on the south east.”
Chris Daems, director of Cervello Financial Planning, said it was no surprise that the regulator was making checks on businesses to ensure they are complying and while this has started in London and Manchester advisers should warn corporate clients that this type of 'spot check' will continue in not just the big cities but spread across the country soon.