N.I. contributions ?

With an increasing amount of people supplementing their main income with a second job or (lucrative pastime) HMRC once aware of such, will ask you for D schedule NI payments on top of your PAYE.  You can, go red and roll around their floor but they will not rescind; they class you as equally disposed between ‘Tax at source’ and ‘Self Assesment’ and as such require self employed NI contributions in addition to Class 4, paid at source via PAYE. Belt and Braces comes to mind either way they will have their pound of flesh!