I understand that the Covid-19 business support grants are taxable. But I cannot seem to find an answer to as to whether they are subject to Class 4 NIC ( and to class 2 as well)? I am completing an SA return for a self-employed client, and his Small Business Grant ( £10k), was received on 3rd April. So it needs to be included in the 2020 return. Does anyone know if it is subject to NIC. In this case the client pays Class2 in any case, but does it have an impact on Class 4 NIC? Any asistance on this would be appreciated.