The employment allowance of £3,000 per year is available to most businesses and charities and can be used to be offset against their employers Class 1 NIC bill. The allowance can be claimed as part of the normal payroll process.
An employer can claim less than the maximum if this covers their total Class 1 NIC bill. Eligible employers that have not yet done so can still claim for the current 2017-18 tax year (as well as make a backdated claim for one further tax year).
The eligibility to claim the employment allowance was removed for limited companies with a single director (paid above the Secondary Threshold) and no other employees in April 2016.
There are a number of other excluded categories where employers cannot claim the employment allowance.