Normal wear and tear versus damage

Wear the landlord absorbs

These come from someone having lived there. They are the cost of renting a place out.

• Carpet flattened along the path from the door to the kitchen
• Small nail holes from hanging pictures
• Faded paint and minor scuffs at chair height
• Worn finish on a door handle or threshold strip
• Loose grout or a hairline caulk crack from age
• A toilet seat or blind slat yellowed with time

Damage they can charge for

These come from an event rather than from time passing.

• Pet urine in carpet or padding
• Cigarette smoke residue on walls and ceilings
• Burns or gouges in a counter or floor
• Anchors, large holes, or unpatched drywall
• A cracked window, mirror, or shower door
• Missing keys, fobs, remotes, or window screens

Where cleaning actually sits

Dirt is a third category and it is the one people lose money on. A greasy oven is not wear and tear, because it did not get that way from time passing. It is also not damage, because nothing is broken.

It is a cleaning cost, and it is the easiest thing for a landlord to deduct, because a cleaner's invoice is a real number they can point at. That is precisely why paying for the clean yourself usually costs less than letting them arrange one.