More than a quarter of households in Scotland risk paying a fine of up to £1,000 after failing to complete the census.
Figures from National Records of Scotland (NRS) show some 700,000 of the 2.7 million households have yet to submit their response.
The survey - which takes place once every decade - is due to close on Sunday.
More than a third of households in Glasgow have failed to complete the census - the worst record in the country.
Angus Robertson, the Scottish Government's constitution secretary, has urged people to complete the form as soon as possible.
"I want to thank the two million households who have already completed the census and met their legal responsibility,” he said.
"But as we enter the final week many returns remain outstanding.
"For the census to be effective in delivering its many benefits for future public services, it is vital that we secure a higher response rate and one that reflects the diversity of our communities.
"Today we are calling on all of our communities and organisations to come together and to redouble their efforts to encourage participation.
"It’s absolutely essential that every householder in Scotland completes the census.”
NRS chief executive Paul Lowe said: “Every single household return is vital to the overall success of the census.
"Census data is vital in informing decisions about services that affect us all.
"We have put in place a number of additional interventions to support those who have yet to complete a return. This includes a range of additional household reminders.
"Our field team have already undertaken more than 750,000 household visits to support those who have not completed, and are continuing to make these visits.”
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