Tax credits estimation of income

[Pooky77]

I'm due to start maternity leave in January and my income for the tax year to 5 April 2017 will be too high for a claim. But next tax year i will make around £18k and my DH £16k so i think we would be entitled to some tax credits.

What i need to know is, when do i make a claim? Straight after baby is born in Feb 2017 or wait until after 5th April 2017, or do i have to wait until 5th April 2018 when i know my earnings for sure? I'm hoping i can just give an estimate of earnings for the 2017/18 tax year and then get the tax credits while i'm on maternity leave but i have no clue if that's allowed or not?

You won't get tax credits on an income of £34k unless you have multiple children or children with disabilities.
Is the 18k including maternity pay because you can deduct that from the total.

Yes without SMP my earnings will be £14k in 2017/18. I entered my estimated earnings for that tax year into the online calculator and it suggested i would get something, i'm just unsure if i'm ok to estimate my income and claim when baby is born or if i have to wait until i know what my earnings are in April 2018?

On 30k total income with one baby? You would only be entitled to wtc for childcare , no child tax credits. The cut off is £25k for one child £35k for two.

Yes I see now that it will only apply when I go back to work and pay childcare. I think I'll make a claim when baby is born which will be nil and then update the claim when I'm paying childcare in November.

I think in your situation there will be little point applying before Nov. You will just cause more paperwork and confusion. If you know you won't be entitled then I would wait.