I've just had my tax credits renewal through, my income has gone down by over 3k this year but on my letter is says they are using my income from last year rather than calculating it on my earnings this year which is what I thought they were meant to do if your income goes down by 2.5k? Even in the letter is says I've told them my income is only 10k this year but it still says they will use last year's income? So I'm getting a few hundr3d less in tax credits but earning about 3.8k less?