Who would be clued up on NI contributions for second incomes, where primary income exceeds the upper earnings limit ?
What you need to do is get a form from HMRC which gives dispensation for your second employer to charge your NI contributions at a rate of only 1%. You'l need to prove that your first income is more than likely to exceed the UEL for them to issue the form.
here's the details... If an employee with more than one job thinks that they will earn in excess of the weekly or monthly UEL in one, or a combination of more than one, of their jobs, they can ask the HM Revenue & Customs National Insurance Contributions Office for permission to defer paying some of the NICs in their other jobs. The HM Revenue & Customs National Insurance Contributions Office will send you form CA2700 if it agrees that the employee may defer some of the NICs they would otherwise have to pay on the earnings they receive from you. This form authorises you to deduct employee contributions at 1% on all earnings you pay to the employee that exceed the ET, including any earnings above the UEL.