Hi @nicole388,
Out of the box, this is not possible in HubSpot but there are workarounds. You could use Zapier to send contacts from HubSpot into a Google Sheet. In this sheet, you’d have to come up with a taxonomy/rule for how to create a code for each contact. You could for example get inspiration this Excel tutorial. With the newly generated code for each contact, you could send these contacts back into HubSpot.
If you have the new Operations Hub Professional, this could also be achieved with custom code in workflows.
Lastly, if you don’t have a specific taxonomy you want to follow, the Record ID might suffice, too. Each record in HubSpot receives a unique ID which can only be occur once.
Best regards!