It’s almost impossible to use Foursquare without seeing duplicate venues on a regular basis; they’re everywhere. Luckily, there’s a relatively simple way to report duplicate venues so they can be merged. Venues are always merged and never deleted, so all the checkins, tags, categories and tips are transferred over.
To report a duplicate venue, simply note the original and duplicate venue URLs and add them to the “Venues to be merged go here!“ proper regional thread (below) on Foursquare’s GetSatisfaction support site. Decide which of the venues has the map pin in the correct position and mark that location as “correct” like this:
A team of superusers monitor those threads regularly for new reports and mark the duplicates in the Foursquare system. A second superuser (Level 2 or higher) will then come along and “complete” the merge. It might take a few days for the merge to be completed, but since all checkins are kept in the merge, it won’t hurt to have duplicate venues in the meantime. The mayorship may not be correct immediately after the merge, but it usually sorts itself out when the next person checks into the venue.
Due to limitations in the current superuser control panel, it’s important to make sure the map pin is correct on the one you submit as the correct venue. All other data (address, phone, etc.) can be copied over as the merge is completed.
UPDATE (5/26): The threads for duplicates and corrections have now been broken out by continent to make it easier to keep up with the threads on GetSatisfaction. If you have multiple duplicates to report, please combine them into a single post since only the 15 most recent posts are shown.