Hi! 

Good question, as this is something that can catch you out if you don’t have a full scope of understanding on how this action truly works. 

This doc does a great job of giving the full story:

https://www.customer.io/docs/deleting-users/ 

The main part to call out is the piece where it details the difference between suppressing a profile at the deletion stage, or just deleting it without suppression.

If you suppress a person:

• You cannot reuse the deleted person’s identifiers until you unsuppress them.
• Any attempt to re-add a person with a suppressed identifier is ignored or results in an error (CSV imports, API).
• Activity attributed to the deleted and suppressed identifier (the person) is redacted. Activity Logs show forgotten (anonymous) entries for suppressed identifiers.

If you don’t suppress an identifier:

• You can reuse a deleted person’s identifiers to create a new person.
• A person you add with the previously-deleted identifier will have no prior data, including their unsubscribe status: the re-added person can trigger previously received campaigns.
• Activity remains attributed to the deleted person’s `cio_id`. If you re-create a person with the same identifier as the person you deleted, the new person does not regain the activity history of the previously-deleted person.

So, it sounds like the latter is what you want to do. It’s a good way to handle your profile limits while also leaving your options open for reactivation.

Hope this explains well enough for you!