If you have Contacts that are entered manually into Saasu or existed in Saasu before you installed RIO Finance then you have existing data.
When RIO Finance runs, it checks to see if the Salesforce Contact is linked to a Saasu Contact and it does this by checking a field on the Contact called the External Id (api name: readymade_saasu__Saasu_Contact_UID__c).
If you have existing data in Saasu, this tool will generate duplicate Contacts in Saasu as it does not try to match to existing data.
To solve this problem, you can manually populate the External Id for the Salesforce Contact.
To acquire Saasu’s Contact ID, you have to first locate the Contact in Saasu and extract the UID from the URL.
Once you have copied this ID into Salesforce, when the synchronisation runs, it will not create a new Saasu contact.
Note: Salesforce Contact details will overwrite the Saasu Contact once both records are linked. THIS INCLUDES NULL FIELDS. Make sure you have all the details in Salesforce before choosing to Sync Contact.