Revisions to the regulations governing automatic enrolment have been released following the conclusion of a Department for Work and Pensions consultation.
The package of regulations - including rules on optional waiting periods and simplification of the scheme certification process - comes after the revised timetable of staging dates was published last week.
Speaking after the publication of the government's consultation response, pensions minister Steve Webb said: "These regulations provide key legal requirements and guidance to help employers start enrolling their staff later this year.
"Automatic enrolment can now begin and start a much-needed seismic shift in pension saving in this country."
The consultation focused on how to implement the recommendations of the Making Automatic Enrolment Work review, specifically optional waiting periods and simplification of the certification process.
It also covered new statutory instruments on special occupations not previously included - seafarers, offshore workers and police not under a contract of employment.
National Association of Pension Funds senior policy adviser Richard Wilson welcomed the announcement.
He added: "Firms now have a clearer sense of what they need to do to prepare for the reforms. This will assist them with business planning, implementing payroll changes, and choosing the type of pensions provision.
"We particularly appreciate that the government has listened to our requests to extend the deadline for issuing waiting period notices from one week to one month. This will help businesses by reducing some of the administrative burden that important reforms like these create.
"Auto-enrolment is a once in a generation opportunity that will help tackle the UK's pensions savings crisis. The injection of clarity provided by the government is very welcome. Now the government has to stick with the new plan and do everything possible to help employers and schemes prepare for the launch of auto-enrolment."
Hymans Robertson head of DC Lee Hollingworth said the government had made some welcome amendments.
He said: "Firstly, the DWP has wisely amended the definition of what is deemed to be ‘basic pay' under the certification requirements to specifically exclude items such as commissions and certain allowances. Without this amendment the certification process would have been wholly irrelevant for the vast majority of employers who do not currently deem a car and other allowances as pensionable.
"The relaxation of the time allowed to issue the postponement notice to one month is also good news, particularly for employers with a centralised HR function serving multi-locations."
He added: "We're now just nine months away from launch day for the biggest companies and the clock is ticking. Preparing for auto-enrolment is a complex, five step process that needs at least 18 months of dedicated time to achieve satisfactorily.
"Large companies are going to have to invest significant resources into preparing for these changes and therefore should be looking to achieve a good return on their investment by getting this process right for themselves and their employees."
TUC general secretary Brendan Barber said the final building blocks of the pensions auto-enrolment regime were in place.
"This is almost the final milestone in implementing the Pensions Commission's revolutionary proposal to compel employers to contribute to pensions.
"It has been a rocky journey - and like others involved in the debate, we have not always been happy with the detail or the time it has taken - but today is one to celebrate what promises to be the most significant change in the workplace pensions landscape for many years - and certainly one of the very few progressive ones."
Final versions of the regulations, accompanying explanatory memorandum and impact assessment, and technical guidance on certifying money purchase pension schemes and the money purchase element of hybrid schemes are available at the DWP website.
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