I don't know in this case, but there are several identifiers that both parties might have (phone number, email address, billing address, name). In the industry,

I don't know in this case, but there are several identifiers that both parties might have (phone number, email address, billing address, name). In the industry, you can sometimes get "anonymized" data that is keyed by a hash of these identifiers, then you can hash your own identifiers and join to deanonymize. This isn't how it works in this case, but I know other companies do this.