I work as part of a team that is small even when full staffed, however we have been down 2 members of staff (1 full time and 1 part time) for a couple of years now and this week lost a further part time member of staff. We have had a few new starters and agency temps in during this time that haven't worked out for various reasons, we currently have a new lady in who is doing well but obviously still in training so is effectively taking a trained member of staff away from their job to train her or answer her questions etc - obviously fine if she is going to stay on, nobody starts a new job knowing how to do it all.
However - due to these staffing issues, I have increased my contracted hours and now work 36 hours a week, with at least another 3 hours a week (usually more like 6+) in overtime. Since taking on the extra permanent hours, even though I am in theory paid for the overtime, I don't see a penny of it as it must take me over some kind of tax threshold and all just gets deducted. In fact I did more overtime this month than last, and my take-home pay was less this month.
Would I be unreasonable to refuse any overtime? Am I actually allowed to refuse overtime? I appreciate that the extra hours are needed more now than ever and I've always been happy to help however I can but the fact is, it's a stressful job anyway made more stressful by chronic understaffing, I'm knackered, I spend very little time with my daughter - I'm not willing to work for free!
Does anyone have any knowledge around this and can offer advice? It's not my employer at fault at all, they are still paying me for my overtime, I just don't actually receive any of it and I'm not happy to work extra hours just to pay more tax!