https://www.taxcredits.inlandrevenue.gov.uk

If you go to this website you can put in your information as a couple and try out different scenarios. It will tell you exactly how much tax credit you will get both working tax credit and child tax credit. It's a little confusing but you can try any combination of salaries/wages and you are not held to it - it's a what if I do this sort of system. Also if you have trouble with this phone the tax credit helpline. The inland revenue are extremely patient and will answer whatever questions you have (unlike any job centre/dss type benefit staff.

I am a single parent and worked out in my case that it was worth working full time nights for 3 months until the summer holidays and my tax credits were worked out for the entire year. COUPLES with children can earn up to £58,000 and still receive credit so it is definitely worth looking into.

Also you can very often claim up to 70% (maximum £70 per week) towards childcare but only for registered childcarers, (unfortunately granny gets nothing!) but this enabled me to put my child into a really good private nursery when she was younger and I worked full time.

Good luck negotiating the British tax system!!

Julia