Bmstrt

Hi, Sorry if it’s not ok to add another question to this thread. I have a full time job that will pay £48500 from August. I also have a second job that is a zero hours contract but I usually make £4500 per year, tax code is BR. The weekly pay in my second job never takes me over the NI threshold. Should I split my tax free allowance between the two jobs or defer NI for the first job?