Supply teaching and tax credits

[NannyPlumBum]

I'm sure this has been asked before but I can't seem to find an answer online.
I have just started working as a supply teacher. I am a single parent with 2 young children so have been claiming child tax credits whilst doing my pgce. Does anyone know if I am entitled to tax credits still and how they work it out based on the variable hours?
I have tried calling them today but gave up. I am also awaiting clarification on earnings from the supply agency, I assume HMRC will ask for these.

Afaik you can get tax credits & working tax credits until you pass a threshold, thinks it's approximately £30k.
HTH

Think not thinks! Ha!

I began supply in January and was getting CTC based on my previous salary. I've just had a large payment as my supply earnings are less. I think you have to predict your earnings and then they adjust your payments when it is due to be reviewed.

Yes, predict your earnings and ring HMRC or submit the change online if earnings are different to last year. But, try and keep a bit of money back if you are unsure whether your estimate is accurate as they will recalculate when you renew next year and present you with a bill if you've been overpaid.