Yes, according to the laws on housing benefits, applicants are legally obliged to refund overpaid amounts of housing benefit.
When HMS gets access to last year's tax returns to confirm income and assets, housing benefits for all of last year, are recalculated on the basis of that information.
If the recalculations lead to a change in the benefits amount, it shall be corrected.
The final settlement may form a debt if the actual assets and income, including capital income, have been higher than the amounts HMS had information on and used in their estimates for the previous year.