For example, a possible match could be identified where a name was the same except that one letter might be different. Possible matches could also be identified where first names and surnames matched, but middle names did not match or were absent in one record but not another. Names can also be matched using 'aliases'. A system can be set up that compares different variations on the same name, which could be used by a person at different times. Matching techniques also need to take account of people changing names.
People also change their names by deed poll.
Where this occurs, matching by surname will generally not find a match with an earlier record using the old name. In these cases matches can be found using first name or given name fields and dates of birth. To assist with the data duplication process, it is desirable to ask voters on their registration forms whether they have changed their names since their last registration, and to ask for their previous registered address. This data, if supplied, can greatly assist in finding out of date entries. Fuzzy matching programs often produce several possible matches with a current record, some or all of which may not be actual matches with the person concerned.