Schengen visit Visa for Spain - Bank statements

[BigMo]

Hi all,

My understanding of the requirements for proof of financial subsistence is that you need c.£500 as closing balance, and need to provide bank statements for three months. However, what's not clear is how long that £500 needs to be maintained for? For example, does it need to be in the account as minimum balance for the entirety of the three months, or does it just need to be the closing balance?

Thanks in advance.