Why do UK student visa applicants need 28 consecutive days of bank statements?

The UK Student visa requires you to hold the required funds for at least 28 consecutive days, ending no more than 31 days before your application date. This prevents applicants from temporarily borrowing money. Funds must remain in your account continuously — withdrawing and redepositing resets the clock. Required amounts: £12,006 (London) or £9,207 (outside London) for 9 months, plus CAS tuition fees.