GOV.UK
Examinations: Information: Changes of Circumstances (CoCs) - Increasing the maximum rate of entitlement: Statutory authority
You have the same right to ask questions when claimants notify changes of circumstances (CoCs) increasing the maximum rate of entitlement as you do when they make an initial claim.
S15 says that:
Where notification of a change of circumstances increasing the maximum rate at which a person or persons may be entitled to a tax credit is given in accordance with regulations under 6(1), the Board must decide whether (and if so, how) to amend the award of the tax credit made to him or them.
Note that S15 only applies to CoCs which may
increase the maximum rate of entitlement, and that it does not apply to any changes in income the claimant(s) tell us about in-year, even if the change would increase the award.
If you are examining a CoC which decreases, or does not affect, the amount of the entitlement, or which notifies a change in income, you must use the powers at S16.
S15 powers are rarely used because most change of circumstances are actioned by the TCO or the Contact Centres. However if the risk team identifies a Change of Circumstance (CoC) increasing the maximum rate of entitlement for examination before that CoC is processed, your examination will be similar to ones carried out pre-award, but the statutory authority will be S15. You should follow the guidance on examinations following a CoC at CCM4350.