The main consequences

Consequence	Detail	Status when checked
Advertising ban	You can't market a property to let without active landlord and property entries, and written adverts must show the database ID numbers (s.82)	in force for specified purposes
Civil penalty	Up to £7,000 from the local council for breaching the registration duties (s.91)	in force for specified purposes
Possession	A court can't make a possession order while you're in breach, except on Ground 7A or 14 for anti-social behaviour (s.90)	in force for specified purposes
Offences	Knowingly giving false information, or continuing or repeating a breach, can lead to a penalty of up to £40,000 or prosecution	in the Act, not yet in force
Rent repayment orders	Tenants can apply to recover rent for the registration offences	in the Act, not yet commenced

"In force for specified purposes" means the section has started only for some purposes, typically the setup of the database. Expect the enforcement parts to apply in each region after its deadline.

Who enforces

Local housing authorities enforce once a region's deadline has passed. They can also verify, correct or remove entries on the database (draft regulations, reg 13).

What a breach doesn't do

A breach doesn't make the tenancy invalid. Your tenants keep their rights and you still owe your obligations (s.82(5)).

Joint landlords

The possession bar applies if any one of the joint landlords is in breach. Each joint landlord makes their own landlord entry, linked to the shared property entry.

Avoiding all of it

Register before your region's deadline, keep the entry renewed every 12 months and update changes within 28 days. Use the deadline finder and the checklist to plan.