VATTOS5135 | Actual tax points: payments: security deposits
From HM Revenue & Customs · VAT Time of supply
Deposits may be required as security for the safe return of goods on hire or loan. These payments do not normally represent consideration for a supply and their initial receipt does not therefore create a tax point. If you require further information on what constitutes a security deposit you should consult the manual covering supply and consideration. A payment tax point can be created if, for example, hire charges are later off set against the refund of what was originally a security deposit. But only where this happens before the basic tax point on completion of the hire period.