Change in NIC on becoming a director

[Bosh]

Can anyone tell me why my NI contribution should increase on my appointment as a director? I was appointed on 1/1/07, and my NI contribution has shot up by £400 in the month - I understand it is calculated on a cumulative basis (I don't know why) but surely the amount payable shouldn't increase?

[Peter D]

http://www.hmrc.gov.uk/nitables/ca44.pdf

May help. Regards Peter

[Bosh]

Thanks Peter. Still don't know why a director should be treated differently though!