tax credits notify change help

[jenb]

hi everyone

before i had my daughter i worked full time, when my maternity leave ended i returned to work part time which was on 26th march, i have not yet told them of my change yet as i totally forgot and i only remembered when i got my tax credit renewal in the post last week, so since then i have been on the helpline many times a day and ive been left waiting for ages and noone picks up so i havent got through to anyone yet

now...i know it wont effect how much money i get as it will be based on my income from 2011-2012 tax year so can i just leave it and when i get my tax renewal pack next year just update my salary? or will i still need to let them know i am now part time even though it wont affect me untill next year?

its all so confusing