By default, Import2 does not affect any pre-existing data in your destination database. Wherever possible, we create new entries for imported data.
Please consult the tool-specific FAQs to confirm what is possible with your tool.
If you need us to make changes or merge imported records to your pre-existing data, please note that this will be a customization and we would need to discuss the details together prior to the full import. Please contact us here via chat to get the conversation started.