Census returns for England and Wales are subject to a 100-year non-disclosure rule. Copies of census returns are available for public inspection for the years 1841, 1851, 1861, 1871, 1881, 1891 and 1901 only. Not all census returns have survived, there are some original census enumerators books missing or damaged beyond repair and have not been microfilmed.
The householder was to complete their individual household schedules recording who was in their household during the period Sunday night to Monday morning. On the morning after census night, the census enumerators collected the household schedules. If these were not completed properly, the census enumerator was supposed to ask for extra details at the doorstep, although there is considerable evidence that this was not done uniformly. If the householder was unable to fill in the schedule, perhaps because he or she was illiterate, the census enumerator was to fill it in for them. For example, In 1871, the majority of some Welsh-speaking parishes in Anglesey were filled in by the enumerators.
These individual household schedules were then transcribed into the census enumerators' books, together with statistical information, and it is from these books that copies of the census returns can be obtained.
A considerable number of people were not in normal households on census night and special arrangements had to be made for their enumeration. These people included the inmates of institutions, the crews of vessels afloat, the army, itinerants and travellers, and night workers.