Is it possible to add 3rd party validation in supplier registration process

Summary:

Is it possible to add 3rd party validation in supplier registration process

Content (please ensure you mask any confidential information):

The business case / scenario is as follows:

The client has its own database with a huge number of what they refer to as Legal Entities - basically parties.
That system is a repository for banned parties.
Therefore, what they want is to validate supplier details from their own database.
If there is a match in their database, that supplier should not be created and wait in supplier registration.
This validation has to happen before an approval notification is sent for supplier creation.