Random Change of Tax Code as of about August time - what might have happened?

[Sycamoretree]

I have just noticed (because I'm not terribly good at keeping track of these things) that my pay is down by about £120-£150 per month since around August. I have been informed by our accounts dept that my tax code has changed, but I have not been informed by HM Revenue and Customs. There has been no change to my salary or tax deductable benefits. Can anyone shed any light on what's going on? It looks like I'm not the only person it has happened to at my office.

It might be something to do with the the change in tax allowamces for the reversal on the introduction of the 10p rate of tax earlier in the year. Your employer should be able to explain this to you properly or give you number of relevent tax office help line to go through things

Thanks WAP - our HOF did mutter something about 10 p tax but I am SO clueless, I don't really know what it means. Have their number now to call.

Do you have a P11d - I'm sure my tax code only changed around that time as a result of my P11d.

your tax code should have changed for september as a result of the emergency budget (the 10p tax rate thingy) but your pay should have gone UP as a result of that not down.
looks like either they may have had you on the wrong tax code at the start of the year and only realised in august? i dont know what your salary is (ie if it is humungous this is only a small change) but assuming you're not a zillionaire that is quite a lot to lose. is it possible you underpaid tax last year and it is being claimed back through your code or you had something to pay tax on (savings, freelance income that you declared on a tax return) which is now being reclaimed through your earnings this year?

My P11D status has not changed - I've had the same benefits for around 8 years now. I'm not a zillionaire, but quite well paid I supposed (over £50K) but yes, this is money sorely missed as my DH is a SAHD so this is sole income.

It could just be a mistake- that happened to me a couple of year ago... I rang the tax office, and they corrected it, as nothing had changed in my employment.