All non-HubSpot form submissions from the same browser and device will be associated with a single contact.
Deduplicate companies by company domain name.HubSpot deduplicates objects that are created in the CRM (e.g., imports, forms submissions) in the following ways:
Users in a Professional or Enterprise account can also manually manage possible duplicates by using the duplicate management tool. You can include Record IDs in your import file to deduplicate records via an import. Record IDs can also be used to deduplicate contacts, companies, deals, tickets, products, and custom objects.
HubSpot automatically deduplicates contacts using email addresses, and companies using domain names.