NSW and QLD have the same ruling which states that a landlord can carry out four inspections in 12 months. You do however need to give seven days notice and provide the correct forms to the tenants before entering the property. Your property manager can assist with this process by providing issuing the tenants with the appropriate forms based on what state your investment property is in.
If under certain circumstances you are required to attend the property on a regular bases such as mowing the lawns, doing the gardens or doing the maintenance then this should be discussed with the tenants prior to signing the lease and a special arrangement can be made.
Landlords are legally required to abide by the states legislative act which requires them to give seven days notice and limits them to 4 inspections per year. If there a special circumstances this should be noted prior to the tenancy period with the property manager who can take the appropriate steps put it in then tenancy agreement.