HBR 79(1) clears this up to avoid any confusion –
[i:2c5217b3f2][b:2c5217b3f2]Date on which change of circumstances is to take effect[/b:2c5217b3f2]
79. —(1) Except in cases where regulation 34 (disregard of changes in tax, contributions, etc) applies, and subject to regulation 8(3) of the Decisions and Appeals Regulations and the following provisions of this regulation, and to regulation 80(5), a change of circumstances which affects entitlement to, or the amount of, housing benefit (“change of circumstances”) shall take effect from the first day of the benefit week following the date on which the change of circumstances actually occurs, [u:2c5217b3f2]and where that change is cessation of entitlement to any benefit under the benefit Acts, the date on which the change actually occurs shall be the day immediately following the last day of entitlement to that benefit[/u:2c5217b3f2].[/i:2c5217b3f2]