As you import your contacts into First, we are checking the information you provide with our data sources. If a match is found between our data provider and a contact that you have uploaded we will append any information we have found about the most recent address to your contact. Seeing wrong addresses? No worries. We know that data isn't always perfect. We recommend updating the property address in your First app to their known address or mark the property as Wrong Property on the Contact Profile Page so that we continue to provide more accurate information to our users.