People living in six counties across the country are being asked to help prepare for the first ever online census.
The CSO is inviting those in Mayo, Offaly, Louth, Dublin, Kilkenny and Cork to take part in the Census Pilot Survey.
The Census Pilot Survey is taking place in 44 locations across six counties.
Locations in Mayo include parts of Ballinrobe, Castlebar, Claremorris, South East Mayo and Westport.
It's part of preparation for the next Census in 2027 - that'll be the first time we'll have the option of filling in the Census form online.
The CSO is also testing a number of new questions.
Like where a household's car or cars are parked overnight, to help decide on potential placement of electric chargers - if your gender is the same or different to your sex recorded at birth - sexual orientation - and how you'd self-report your mental health.
The CSO sent letters to households in the chosen areas, giving more information on how to take part.
The official Census Pilot Survey night will be on September 22.
Eileen Murphy, Head of Census Administration, has been outlining why Mayo has been selected as part of the pilot to Midwest Radio’s Rian Bailey:
