As you should be aware from the media, the auto enrolment pension contributions increase from 6 April 2018.
This should automatically happen via your payroll and be paid by direct debit.
According to the pensions regulator, there is no legal obligation to inform staff of the changes.
We don’t inform them of tax changes, which is also decided from above and we have no control over it.
They do suggest that as best practice you let them know.
I would therefore recommend an email to all staff with a link to the government website stating the change in the pension amounts, and advising them to go and take a look.
https://www.workplacepensions.gov.uk/employee/
Any questions, let me know.