The wrong registration type only shows up through its consequences — missing form data, consents that were never collected, or people registering without approval. Some of it can be fixed while registration is open and some cannot, so the first step is identifying which symptom you are seeing.
Getting started
Go through four questions. A yes to any of them means the registration type does not match what you expected:
Do I have people's answers from the registration form?
Are the optional consents (photos, marketing) being collected?
Does somebody have to approve a registration, or does everyone get through?
Does the number of tickets sold match the number registered?
Details
Form data and consents are missing
The most common symptom on paid events. If you chose automatic registration, the attendee never goes through the registration form — they answer no additional questions and grant no optional consents. Your export then holds contact details and nothing else.
You can fix it by switching to registration with additional information, but only for new purchases. For people who bought earlier, the only way to fill the data in is to ask them separately — for example with a campaign linking to the form.
People you did not expect are registering
That means open registration through a public link is running even though you wanted an invitation-only event. The fix is in Registration restrictions: switch to Assigned contacts only, or to allowed domains. Earlier registrations do not disappear — you have to go through those by hand.
Approval cannot be enabled
Approved registration cannot be combined with Tickets. If you created the event as paid and now want to approve everyone, the system will not let you. The workaround is to use non-public tickets and individual links, letting in only the people you send a link to.
Sold and registered do not match
With registration with additional information that is normal, not a fault: the order comes before the registration. The gap is a queue of work — people who hold a ticket but have not filled in their details yet. You can notify them in bulk from the orders detail.
Common pitfalls
Changing the registration type mid-registration
The change applies going forward only. Data, consents, and approvals are not backfilled, and your list ends up with two groups of people whose details are complete to different degrees. Before you switch, decide how you will even out the earlier ones.
Postponing the decision
The registration type governs what data you can collect at all, and it is cheapest to get right at the start. The decision criteria are in Choosing the right registration type.