Change in income via atlas? anyone know what this means?

Hi everyone

I'm going to give my local council a call on monday - but i've just looked at a new decision which has reduced my HB down to about £4.00/fortnight.....I can't see any circumstance of mine that has changed this year.

It says on their decision form that the reason for the calculation is a 'Change in Income via Atlas.'

Anyone know what this means? Just wondering if i need to call them or is it something temporary or what....

thanks if you can help :-)