1. Create a CSV file using this format:
Note: It is very important to include an External ID as this will serve as a reference key to ensure that the Contacts belong to the same Company.
2. Set Up> Import/Export> Import CSv Records.
3. Import Type = Relationships.
4. Record Type = Prospects and Contacts Together.
5. Select the File > Hit Next.
6. Data Handling = Add or Update > Hit Next.
7. Mapping as below:
8. Hit Next.
9. Enter Import Map Name > Save and Run > Hit Import Job Status > Refresh.