Last year's income

bigonroad

Hey there. Annoying calculation problems. I have three questions at the end!

Last year
Last year, I was a student, with no income.

My wife was unemployed/briefly a cleaner. She never claimed the dole (partly because they told us we would get £3.50 a month). Her total income for 09/10 was about £2000

We had two lodgers, paying towards food and bills approximately £300-500 a month total - very varied. My parents own the house, and we pay rent to them monthly.


This year
Now I am a doctor, I earn £26000 a year gross.

My wife is earning nothing. We are still paying rent to my parents, and we have no lodgers. We pay £82 a month council tax.

We have a baby being born this month.


Questions
1. For working out our pay in 2009/2010, what on earth do we put? Do we include the lodgers, when it was very variable, no contracts, and they paid us what they could afford, helping with food, bills and rent costs?

2. How much should we be due tax credit wise? Very roughly...

3. Will we be penalised when it turns out our 2010/2011 income is more than our 2009/2010 income? Will we have to pay back money?

Thanks!
Chris