Not necessarily. While some councils do backdate, they are not legally obliged to – each council can decide their own policy.
For example:
We’ve heard some councils do not backdate at all;
We’ve heard from several users that their council backdated the discount by six years;
We’ve also heard that many councils backdate to the point that the individual was receiving a certain benefit, such as attendance allowance.
All the above approaches are legally permitted, as there is nothing in law which says a council has to have a particular backdating policy.
However, following MSE campaigning, Wales has standardised its backdating process and all 22 Welsh local authorities backdate the SMI discount to when you were diagnosed as becoming SMI (note this could be prior to when the diagnosis is actually made). MSE wants the rest of the UK to take up this approach to backdating and is currently campaigning for this change.