FYI: THIS IS SUPER ILLEGAL

A landlord MAY NOT keep your deposit over ‘normal wear and tear’. They may ONLY collect on something that is YOUR FAULT. They cannot charge for carpet wearing down or needing a new coat of paint after a few years, or the furnace needing a replacement because it’s old. They can charge you for punching a hole in the wall that you never fix, or spilling paint on the carpet requiring a specialized cleaning or replacement. And they may ONLY keep what covers the repairs (If insufficient, then and only then may they keep the whole deposit, as in your deposit did not cover the damage you caused). 

KNOW YOUR RIGHTS AS A TENANT. You landlord MUST return your deposit unless it was damage you directly caused, and ONLY the amount needed to fix the damage, and not one penny more. 

If there is any damage to the unit when you move in, DOCUMENT IT. Take photos and make sure they’re dated.

If something breaks while you live in the unit, and you can’t fix it easily yourself, REPORT IT. Make the landlord deal with it. 

Document what the unit looks like when you move out, before the final inspection–because landlords can and will try to fake damage. Have proof of what damage was yours, if any, and what damage was not. 

Landlords will try to fuck you out of every penny you have, including in ways that are horribly illegal. Don’t let them.

Make sure they’ve sent your deposit to a government holding scheme too, you should get a reference number directly from the scheme (like Safe Deposits Scotland for example) NOT from your landlord, within a month of paying the deposit. If you don’t receive any such reference number or suspect your landlord is holding onto your deposit themself, contact a tenants union. If you suspect they’re lying about the condition of the property when you moved in or out, make sure to take time-stamped photos and send them directly to whatever holding scheme has your deposit as well as to your local tenants union. For Scotland you can contact Living Rent, in England and Wales the tenants union is ACORN.

All that said, there’s an easier trick that’s become sort of custom around here which is simply to never ever pay your last month or two’s rent (you need to be in at least 3 months arrears in Scotland for grounds to evict) and take that as the deposit.