NIM02300 - Class 1 NICs: Earnings of employees and office holders: Horse racing - prize money
The distribution of Horse Racing prize money to stables is the responsibility of the British Horseracing Authority (BHA). Their rules are quite specific on the distribution of such monies.
The distribution criteria of the amounts of that prize money to be paid to stable employees is for those employees to decide (BHA rule 119) and is made in line with ‘tronc’ arrangements, income tax but not NIC is accounted for by the Trainer (as independent Troncmaster) on such distributions.
For more guidance about when payments of gratuities (Troncs) can be disregarded from earnings when calculating Class 1 NICs liability see NIM02900.