Staff working for the Scottish Government intend to collect additional data via the so-called Census Coverage Survey in a door-to-door move that began in June.
Paul Lowe, Registrar General for Scotland and Chief Executive explained: “Even if you have completed the census, you may still be asked to take part in the coverage survey.
"It’s really important to participate if asked, as the information you provide has a direct impact on your local community, from the building of new schools and hospitals to improving transport links and understanding health needs.”
CCS staff carry ID and their identity can be checked with a free telephone helpline on 0800 033 4010.
They will never ask people for financial information like their bank account details and will not ask for money.