For council tax discount we can consider backdating your claim for up to 3 months.You have to prove 'good cause' for not claiming earlier but we must take account of all the facts of your case.
The reason must apply for the whole period you want benefit to be backdated for.
In certain circumstances, it may be possible to award benefit / reduction from an earlier date. The maximum amount of time that your claim can be backdated is different for Housing Benefit and Council Tax Reduction claims.
The maximum period a Housing Benefit claim can be backdated for working age customers is one month from the date you request it.
We can only do this if you are liable to pay rent or council tax during this period and you are entitled to claim.
If this is the case, we will write to you to ask for further details if we do not have them.