A review of empty houses is being carried out in Bushey and Radlett.
Hertsmere Borough Council has started the review of properties across Hertsmere where council tax is being paid but which, according to records, are empty.
The review aims to determine if the properties remain empty or have recently become occupied.
Councillor John Graham, portfolio holder for finance and property, explained: "We have a duty to maintain accurate records for council tax in order to ensure that allowances, discounts or relief are claimed correctly.
"By getting more empty homes back into use, the council receives a new homes bonus from central government, helping us to maximise revenue and maintain services at a time when budgets are severely squeezed."
Letters are being sent to around 250 property owners, and if no responses is received, these will be followed up by visits to determine the current position with the properties.
Further information can be obtained by contacting CapacityGRID on 0845 241 9565.