People should watch out for an "extremely convincing" scam that may redirect victims to the official Post Office website, Which? has warned.
The consumer group said it has seen variations of texts claiming a parcel delivery has failed and asking recipients to click a link to book or reschedule a delivery.
Clicking on links may take people to convincing cloned online sites, Which? said, and they are asked to fill in their personal details, putting them at risk of identity fraud.
