Protect the deposit within 30 days
From the day you receive the deposit — not the day the tenancy starts.
Section 213(3) of the Housing Act 2004 requires the deposit to be paid into an authorised scheme — DPS, TDS or MyDeposits — within 30 days of receipt. The clock starts on receipt of cleared funds, not on the tenancy start date, and not on the date the tenancy was signed. If you hold the money on the 1st and the tenancy starts on the 15th, day 30 is the 30th of that month, not the 14th of the next.