In the Budget 2020 statement the government announced that Local Authorities in England will get £500 million of new grant funding to support economically vulnerable people and households in their local area. Guidance was set to Local Authorities in March 2020 outlining what the government planned to do with this money:
'The Government’s strong expectation is that billing authorities will provide all recipients of working age local council tax support (‘LCTS’) during the financial year 2020-21 with a further reduction in their annual council tax bill of £150, using their discretionary powers to reduce the liability of council tax payers outside of their formal LCTS scheme design.'
In other words, where someone is liable for the Council Tax is working age and getting Council Tax Support/Rebate then their Council Tax account should be credited with £150 or until the Council Tax bill is zero. This level of £150 can be increased by individual local authorities depending on how much of their grant allocation is left.
Note that the minimum required to be paid by all working age bill payers - set by local restrictions - is ignored for this purpose (for instance where the local scheme restricts entitlement to 85% of liability, the full amount of £150 should be credited even if this means that the bill payer now has less than 15% to pay themselves).