Lessons Learned with Multiple Zoho CRMs and Invoice Integration

I have been using Invoice for a little over a month now and have learned a few lessons along the way.
I hope this will help someone avoid the same mistakes.

I have multiple CRM accounts based on the type of services as custom fields required are unique to the type of client.
A number of customers are in multiple CRM's.
CRM 1 had Accounts and Contacts linked to the Accounts.
CRM 2 had mostly Contacts as these were individuals and not companies.

I have one Invoice account. Invoice allows you to import contacts via CSV and CRM.

If you are planning to use CRM for customers, use one CRM to create and all customers. Otherwise you could have duplicates.

I imported customers from one CRM successfuly, Then tried changing the API key to import from the second CRM. It didn't work at first. CRM 2 needed accounts with names and addresses.

So I created csv files to import customers and contacts from CRM #2 as a temporary solution to get them loaded in Invoice. Basically I used the CRM contacts CSV file but manipulated the headings to import it first as an customer and then as a contact.

Later I learned that import customer api keys are associated with ZI users. So user 1 can import from CRM 1, and I needed a user 2 to import from CRM 2.

I created user 2 and imported from CRM 2 expecting the import to update customers I'd created through the csv. Not so.

Lesson learned - Invoice tracked customers by their source of creation. A CRM record will not update a record created manually in Invoice or imported via CSV, It first imports records from the CRM, then updates them upon request.

Lesson learned - If you have the same customer in multiple CRM's you will get duplicates. Invoice tracks which CRM the customer was created. It also makes the customers created from the previous CRM inactive. Yuck!

So now I have one Master Client CRM (which I'd been working on concurrently anyways). I rebuilt a new Invoice account to link contacts from my Master CRM. My policy is to create new customers in the Master CRM first. Never create a new customer in Zoho Invoice or Import a new customer.

Next on the agenda is to figure out how to get the 3 CRM's to work together to keep the addresses and contacts current on all CRM's.

If you have multiple CRM's and you are integrating with Invoice or other Zoho products, please share your story. I've not seen many topics on this.