For Class 1A NICs liability to arise the benefit provided must not attract either a Class 1 or Class 1B NICs liability.
Some benefits, such as non-cash vouchers, are liable for Class 1 NICs, see NIM02411. Where a liability for Class 1 NICs exists, Class 1A NICs are not due. For a list of items which attract a Class 1 NICs liability see NIM2010 onwards.
Some benefits, which are minor or irregular, or difficult to
apportion between employees, can be included in a PAYE Settlement
Agreement (PSA). For further guidance on PSAs see the PAYE
Settlement Agreement Manual.
Those benefits included in a PSA, which would otherwise attract Class 1A NICs liability, attract a Class 1B NICs liability instead. Where Class 1B NICs liability exists, Class 1A NICs are not due. For guidance on Class 1B NICs, including examples of the types of benefits which are likely to be included in a PSA, see NIM18000 onwards.
Dual NICs liability
There are no occasions where a liability for Class 1 and Class 1A NICs should exist on the same benefit. Unless specifically excluded from Class 1A NICs liability, where
those general earnings are liable for Class 1A NICs. Details of those general earnings specifically excluded from Class 1A NICs are given at NIM14000 onwards.