Having recently submitted a client's SA Return I was surprised to receive a correction from HMRC, as I tend to undertake manual calculations (old school ) as well as using Taxcalc.
The client has 2 PAYE employments, and one self employment and a high rate taxpayer.
The issue arises with the treatment of NIC from multiple sources.
HMRC's computer system ignored the reduced liability due to Primary Class 1 Contributions, and calculated the Class 4 NIC in the normal manner creating a higher liability than due.
I spoke with HMRC, who were helpful in as much that their NIC knowledge may be limited and advised they could not follow my calculations. I was advised to contact the NIC Office, which I did.
They were able to undertake their own manual calculations and agreed my figures. As I understand, this needs to be referred to other Departments to put back our figures ( and I suspect to correct the system.)
I have posted this to empasise that HMRC calculations for NIC in certain cases may be incorrect at this time.
