June 2015 is one of the dates after which firms (in this case with fewer than 50 workers) will begin enrolling their staff into a Workplace Pension Scheme
A Workplace Pension is a saving scheme for retirement organised through an employer. The employer may have their own scheme, offer one from a specialist pension provider or use a Government backed scheme. Subject to acceptance of the scheme, millions of workers in the UK will gradually see a slice of their pay packet being automatically diverted to a saving pot for their pension. Employers are obliged to pay in as well with the Government adding a little extra through tax relief.
Automatic enrolment began in October 2012 with staff who worked for the bigger businesses. There is a rolling program over 6 years to bring in the vast majority of UK workers.
There is no obligation to take up the scheme but you will need to opt out rather than opt in. You might opt out if you decide that you need all of your monthly pay to make ends meet or you have a private pension policy that you think is sufficient.
More information can be found from the Work Place Pension section of the gov.uk website.