The rent amount must be stated in advertisements or offers for the property. This does not apply to service tenancies.
Landlords cannot invite or encourage prospective tenants to pay more rent for a property than is stated in the advertisement or offer. This means they cannot organise an auction over a rental property, or offer to give the rental to a tenant if they agree to pay more for it.
Prospective tenants or any other person can still voluntarily offer to pay more than the stated amount of rent and a landlord may accept this offer.