Tax Code Help

[Most Easterly Pandas]

I've tried googe and HMRC site but not a lot of information on what I want to know.

Two tax codes - '937L C' and '937L N' what is the difference? What does the N mean and what does the C mean

Edit, found out it means Cumulative vs Non Cumulative. Hmmmmm.

 

[Stu DemonD]

Non-cumulative as in Week/Month 1 and Cumulative without that flag.

 

[Most Easterly Pandas]

Stu, are there disadvantages of being on Non-cumulative if I always earn enough to pay tax each month?

Some at work think they've over paid tax on their bonus this month if on Non-cumulative, but having had a look online as to exactly what the differences between the two are, this may only be an issue if one month I didn't use my full tax free allowance and it wouldn't have been transferred to the next month. But I pay tax and use my full tax free allowance every month, so am I correct in believing that this is unlikely to be the case?

I hope this makes sense, and that I've even understood it correctly