Partner applications normally wait in your review queue until someone on your team opens them and clicks Approve. Auto approval writes that decision down as a set of conditions, and applies it the moment an application arrives. Anyone who does not match still waits for your review.
When someone applies through your partner application form, auto approval runs once, straight away, and only for partners who applied through that form — a partner you add yourself is never touched by it.
If the application matches your conditions:
it is approved without anyone on your team doing anything,
the partner is emailed their sign-in link immediately, exactly as they would be after a manual approval,
your team is told they were approved rather than asked to review them.
If it does not match, nothing happens to the application: it sits in your review queue as it always would, and your team gets the usual notification.
A condition is a reason to let someone in. There is no rule that turns an application away — an application that does not match simply waits for a human. That means the risk sits entirely on the side of being too generous, and an approval cannot be taken back once the sign-in link has gone out.
Conditions are built from the partner record: the partner type they applied as, and your own partner fields. A field you put on the application form carries the applicant's own answer, which is what makes this useful — you can approve on what they told you.
A field you keep internal is still offered, but a brand-new applicant has no value for it.

The partner record also offers history properties — Lead Count, Partner Score, Total Revenue, Time Since Joined and so on. An applicant has no history, so these sit at zero rather than being unset. A condition like "Partner Score is at least 0" or "Time Since Joined is under 7 days" therefore matches everybody, which is almost never what you meant. Build your conditions from the partner type and your own fields instead.
Underneath your conditions is a preview: pick a real partner and see whether they would pass. It changes nothing about that partner — it just shows you the answer.
Bear in mind that an existing partner has real history behind it, so a condition over Lead Count or Partner Score behaves differently for them than it will for a brand-new applicant.
You can build and test conditions with auto approval switched off. Nothing happens to a real application until you turn it on.

Auto approval turned on with an empty condition list approves every application that arrives. We warn you before that can happen, and the page keeps showing a warning for as long as it is the case — but it is worth stating plainly, because it is also the state you reach by deleting your last condition while auto approval is on.
Every run is recorded. The most recent ones are listed beside your conditions, each showing what happened and why — including the applications that were left for review, with the conditions they failed. Open one to see the individual condition results.
