Sometimes your table may contain records that have the same address, but lie in different towns. If you only geocode by street address, MapInfo Pro cannot differentiate among the records to give each one unique coordinates.
To solve this problem, MapInfo Pro allows you to geocode against a boundary in addition to the street address to find the correct match.
For example, you want to geocode your database of records in Cook County, Illinois. One address in the database reads 200 Washington St. Within the county of Cook, there are eight towns. Four of these towns have a Washington St. Three of the four towns have a 200 Washington St.
By telling MapInfo Pro to search against the street table and a boundary table, there is a much better chance of finding a correct match. MapInfo Pro can then differentiate between 200 Washington St in Chicago and 200 Washington St in Urbana.
To refine a search, select the column in your table that contains boundary information (TOWN, CITY, POSTALCODE). Next, select a MapInfo Pro table that also contains that boundary information you need. If you purchased your county street map from MapInfo Pro, two of the files included are FILENAMES.TAB (where filename is the state and county abbreviation), which contains the street information, and FILENAMEMC.TAB, which contains the town boundaries (minor civil divisions) for that county and FILENAMECB.TAB (city boundaries). Use these files to refine your search.
When refining your search, it is sometimes better to use postal codes rather than town boundaries. Town boundaries tend to fluctuate more than postal code boundaries. Furthermore, town boundaries are subject to regional interpretation.
If refining the search with a boundary is still not enough, you can search in additional boundaries for the match. Choose the Options button in the Geocode dialog box to bring up the Geocoding Options dialog box. Select the item that is labeled Use a match found in a different boundary.