Central Otago District Council communications co-ordinator Maria De Cort said council recently identified event signs, hoardings and vehicle/trailer signs that breached district plan rules.
About 150 letters would be mailed out this month and those who received letters would have to remove their signs.
Ms De Cort said the district plan contained sign rules to avoid cluttering the landscape.
Some signs were allowed on the property they related to, or for a temporary period such as advertising an event.
But generally advertising hoardings were not permitted.
Signs placed or fixed to vehicles or trailers parked on private or public property (including roads), where the apparent purpose was to advertise or to direct people to a business or nearby property, were also not allowed.
