If you do not clean properly during your stay and at the end of the tenancy:

the property may suffer damage (for example mould, deep stains, strong odours),

the landlord may need to pay for professional cleaning, deep cleaning or special treatments (e.g. mould removal),

these costs may be charged to you or deducted from your deposit,

serious neglect can also be considered a breach of contract.

Good, regular cleaning helps protect your deposit and keeps the property pleasant for you and any future tenants.

In case it leads to damage to the property or amenities the landlord has the right to cancel the tenancy agreement earlier than it’s expiration.