Keywords: Address quality, Data quality, Addresses, Address database, CRM, ERP, Duplicates, Duplicate check, De-duplication, Consolidation, Selectivity, Software.

De-duplication in Address Databases

To maintain a duplicate-free address database of CRM-, marketing- or ERP-systems all entry points for new addresses have to be monitored. These are:

  • Interactive address maintenance (creating and changing of addresses by users)
  • Address imports

Depending on the application further entry points might exist. However in principle it is always one of the two above mentioned variants.

De-duplication in Case of Interactive Address Maintenance

Interactive duplicate check means that in case of interactive address maintenance each new or changed address of a CRM-, marketing- or ERP-system is checked individually.

As this interactive duplicate check should be very fast the address basis must be prepared, this is done by fuzzyification and indexing (Fuzzyindex).

Now, the duplicate search proceeds as follows:

  • For newly entered or changed addresses duplicate candidates are searched in the inventory and displayed to the user.
  • The user decides if the displayed candidate is a duplicate or not.
  • If, for a newly entered address a duplicate is found, the user proceeds with this address.
List of candidates for a created new address.

If duplicate addresses are found in the database, then these duplicate addresses cannot just be deleted. It already fails technically as the systems mostly do not allow any deletion but only a deactivation of addresses.

However the main problem is that more and different information like orders, invoices or marketing information might be linked to the duplicates. There is no easy answer for how to proceed. An obvious solution would be to change the link of the information to the new address. This is not only easier said than done, but it is also problematic because for example invoices must not be re-linked to new customer records (with new customer numbers). The more complex the application is and the more information are linked to data records, the more difficult is it to merge the data.

This problem, or even impossibility of de-duplication is an especially grave reason to use q.address to prevent the occurrence of new duplicates at the root in CRM-, marketing- and ERP-systems.

Consolidation of duplicates via q.address add-on in Microsoft Dynamics CRM. The “merged” address is made from the marked data fields.

De-duplication in Case of Address Imports

If entire address lists should be loaded in the address database of a CRM-, Marketing- or ERP-System, then it is facilitated analogously to the previously described interactive duplicate check. Address by address is checked whether it already exists in the database.

Other than in case of interactive duplicate check, the decision whether a duplicate exists or not must be made automatically. This automatic decision is made according to the same criteria as in case of inventory cleansing. more…


Product name for the module duplicate check is (“DuplicateCheck”) (“DC”).

Duplicate check (interactive in address databases) is available in:

q.address Integrations

q.address Quality Server

q.address Web-Services

Note: Solutions for address imports can often also be implemented with q.address Stand-alone, preferably with the Command-line-Version, which can be integrated in automated processes easily. more…

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