Tax credits change of circumstances?

[wrongagain]

I left my contracted job within a hospital to just work on the bank and do night shifts.
I now also do bank work in another place too, I work when there are shifts available that suit me.
I have just phoned them to ask about how I would inform them as I do not know how many hours I work a week or how much I may earn.
They weren't very helpful so thought I'd come here and ask advice.

I can work anything between 20-50 hours per week, in two different places with two different pays.
TC helpline told me I need to estimate how many hours I work and how much I'll earn, and which one is my main employer.
it differs each week as to which place I do more shifts in and also the shift hours change depending on where I work.
How the hell do I estimate all this?
Many Thanks in advance.

We are in a similar situation as my husband is self-employed. His hours vay enormously and his pay - you just have to provide a best guess or average for the tax year. Am I right in thinking that TCs are more generous if you work more than 30 hours per week? There is something called 30 hour element - not sure exactly what this is ??

Maybe you could take the average of the last 8-10 weeks (if you've kept a record) and use that as the basis for your best guess? Estimate it a little on the low side if you're not sure. It's better to understate it & find they owe you money when the actual hours/earnings are calculated rather than have been badly overpaid and you owe them money.

Do you have a partner? As long as you work at least 30 hours a week between you, it won't make any difference to your TC.

Sorry, in terms of pay, as long as you (and partner if applicable) don't earn more than 25,000K greater than last year then it doesn't matter too much what you estimate your pay to be - if you earn less than last year you'll get the extra when you renew.