Holding deposit return before serving S21

We’re going through the paperwork before No Fault Eviction Process and realized that we miscalculated the holding deposit and took £12 more than the permitted equivalent of one week rent at the beginning of the tenancy (£150 instead of £138). We used it (with written tenant’s consent) as a part of protected deposit.

Do I understand it right that the whole holding deposit and not just £12 has to be repaid to the tenant? Does it have to come from Deposit Protection Scheme or we can just send T the money? I do understand that it has to be done prior to serving S21.
Thank you.

The fact that we took a few ponds over a week’s rent, makes it a prohibited deposit. However, does payming it into Deposit Protection Scheme as part of of deposit, sorts the matter out?

The Tenant Fees Act just requires that you correct any mistake you make and I doubt there would then be any consequence. What did you do with the rest of the holding deposit? Was it converted to rent?

All of it was put into Deposit Protection Scheme, with T’s written consent, saying that holding deposit may be used as a part of main deposit protected with DPS.

Then it should be no problem