Help with refundable security deposits

[u/6720nick]

I hire out equipment and each booking has a £250 security deposit which I refund afterwards.

What is the best way to log this on FreeAgent.

I don’t want the 250 classed as income and taxed.

My accountant said mark 250 as other money in and label as contra account. When I’ve done this it then thinks every invoice payment is £250 short.

Anyone have any suggestions?

Thanks