How do I find the Contact ID for deleteContact( )

I have a Paid Plan signup form. When a visitor signs up, several actions occur:
1 - the visitor is registered as a Member (name / email / password), then if registration successful,
2- Wix automatically adds a record to Contacts. Then,
3- my code continues to order / purchase the Paid Plan.
If the Plan purchase completes successfully, all is well - the user is both a Members and a Plan Subscriber (as intended).
If the Plan purchase fails, my code attempts to roll back the entire action, the code “deregisters” by deleteUser(id) - where id is the id returned by wixUsers.currentUser.
Is this the same id that I would also use in deleteContact() to remove the related Contact record??