Keeping the customer ID the same for customers you imported from your CRM is easy - but what about customers that you created for the first time on Handshake itself? Since Handshake has no idea what numbering system your CRM uses, it just generates a phony customer ID that looks like
*12345 for the meantime.
Eventually you'll transfer this customer record from Handshake back into your CRM, and it will get a real customer ID (let's say
W00789 for this example).
The next time you do a customer import into Handshake, we need to make sure that Handshake understands that the customer your CRM calls
W00789 is actually the same as the one it thinks is called
*12345 to avoid making a duplicate record.
There are two ways to do this: the easy way and the hard way. Isn't it always the way?
The easy way: Don't change the customer's details
If you export the customer from Handshake into your CRM, then later try to re-import that customer from your CRM into Handshake, and you haven't changed the company name, contact name, or billing zip code, then Handshake will magically figure out that the two customers are one and the same and link them without accidentally creating a duplicate. Hooray!
The hard way: I can't promise I'm not going to edit customers while Handshake is not looking
If you work in a large company and can't guarantee that staff aren't going to change things around between exports and imports, then you will need to rely on the
internal_id column that appears in the exports. As long as you keep this the same for each customer between imports, this will allow Handshake to figure out which old customer records your new import data corresponds to, and avoid making duplicates.
The only thing that makes this hard is that you're going to have to do more spreadsheet surgery to merge the export data from Handshake and your latest customer data from your CRM. Potentially a bit of a pain.
If you fit into this category, then what is probably easier is this: after you pull your Handshake data into your CRM data, export your CRM's customer list straight back into Handshake (with the shiny new customer numbers) before anyone has a chance to mess with the customer details and break the "easy" method above. Then you don't have to worry about all this
internal_id stuff - much less stressful :)