Just received SA302 from HMRC correcting (increasing) the overall liability.
High earner with the Employment income of £109,804 (taxed at source) and Self Employment income of £39,929.
As per P60, Earnings above the Primary Threshold up to and including the Upper Earnings Limit (UEL) amounted to £41,376 (which is correct ) so the maximum amount of Class 1 NIC was paid. In my opinion and general knowledge of National Insurance due, the Self Employment profit should be then taxed at 2% rather than 9%.
Therefore Class 4 NIC due should be as follows: (£39,929 - £8,632) x 2% = £625.94 This is also how Taxfiler has calculated the liability (and Class4 on SA110 page on tax return was entered as £625.94).
SA302 received from HMRC calculates Class 4 NIC due as (£39,929 - £8,632) x 9% = £2,816.73
I just spoke with HMRC and the agent has referred the calculation to another different department for checking and amending if applicable.
Am i correct with my calculation or is there any special case here, where the Class4 @2% do not apply?
Your thoughts are appreciated. Thank you in advance!