A landlord, or his agent, or someone authorised to act on his behalf has a right to view the property to assess its condition and to carry out necessary repairs or maintenance at reasonable times of the day. The law says that a landlord or agent must give a tenant at least 24 hours prior notice in writing (except in an emergency) of such a visit. Naturally, if the tenant agrees, to allow access without written notice, i.e. agrees by telephone, that is acceptable.