Tax Help Needed

System

YumYum wrote: »

Thanks for all the advice! I assume that they're not aware of the underpayment yet as according to them my employer from the 2nd job hasn't sent them the information for that tax year and I have not yet posted off my P60 yet (it all happened late this week and i'll be posting it off next week once I receive a letter from the IR to double check that i'm sending the right documents to the right address!). The overpayment is around £400 so it's over double the underpayment. I don't have any issue with paying tax, it's just irritating to feel like I might end up getting penalised later down the line for someone else's mistake when I did everything I could to inform them at the time of the change in jobs. I'll try and fight it if it gets to that but i'm not crazy enough to avoid paying the underpayment and then have them slap some penalities and interest on it! Again, thanks for the advice!

Have a look at the P60 and see what tax code that employer was operating at the end of the 08/09 tax year. It should show 603L w1/m1 or 603Lx which means it was operated on a non-cumulative basis. Then you can check with HMRC what code they actually issued to that employment when they changed it to be your primary source.