Edge cases and restrictions

This list describes real situations that arise at the door and how to handle them. Each case includes how to recognize it, what to do, and a cross-link to the matching scan state.

1. Duplicate scan (already checked in)

A guest was already checked in successfully and returns to scan again.

• If the event has check-out enabled: re-scanning auto-checks-out the guest (blue “Auto checked out” screen). The next scan checks them back in — suited to events that allow re-entry.
• If the event is single-entry: a yellow “Already checked in” screen shows the previous check-in time and door name. Do not admit unless policy allows — escalate to the organizer.

2. Scanning during a network drop (offline)

The network suddenly drops mid check-in.

• The scanner automatically switches to offline mode: check-ins, check-outs, and manual lookups are cached on the device and auto-sync when the connection returns.
• The offline success card is the same green guest card as online, marked with an amber Offline badge and a “queued locally” note — reassure the guest the scan was recorded.
• Each cached scan carries a timestamp so the system orders them correctly on sync.
• The “No Ticket” search keeps working offline against the device’s cached guest roster, and re-scanning a QR whose check-in is still queued shows the yellow already-checked-in card straight away.
• Replays are re-validated server-side against the live check-in window — an out-of-window replay is kept in the sync report as a blocked item, not recorded as an admission.

Tip

Only transient network failures (no response, transient server errors) fall back to the offline queue. Input or invalid-ticket errors surface immediately to avoid replaying invalid scans.

3. Invalid or unreadable QR

The camera cannot scan, or the system returns an “Invalid QR” result (red).

• Ask the guest to reopen the ticket on their phone, increase screen brightness, or reprint the PDF.
• If still failing, use manual keyboard entry of the ticket number or look up by name/email (see case 5).
• QR not found in the system — confirm the guest actually holds a ticket for this event.

4. Ticket belongs to a different event

The scan path never compares the scanner’s event to the ticket’s event, so a ticket from another event surfaces as “Invalid QR” (red).

• Do not admit. Redirect the guest to the correct event.
• Common when a guest holds multiple tickets or confuses same-day events.

5. Lost phone / no ticket (“No Ticket”)

The guest arrives at the door without a QR code.

• Tap the “No Ticket” button on the scanner.
• Search the guest by name or email.
• If an active ticket is found — proceed with manual check-in (recorded with the “Manual lookup” method).
• If no ticket is found — do not admit; escalate to the organizer for support.

6. Re-check-in / undo

You need to reverse a check-in.

• Event with check-out enabled: use the check-out feature (or re-scan to auto-check-out, see case 1).
• Single-entry event: only the organizer can undo — door staff escalate to the organizer. Organizers can follow the steps to clear or reinstate a check-in on the Manage check-ins page.
• For more on re-entry policy and check-out, see Re-entry and check-out.

7. Door is at capacity (full)

The door capacity has been reached — amber “Door full” screen.

• Redirect guests to another door that still has space, or wait for check-outs to free up slots.
• Capacity is computed in real time based on how many are currently inside.

8. Outside the check-in window / multi-day events

The current time falls outside the check-in window.

• Before start time: “Check-in not open yet” (ask guests to wait until the doors open).
• After end time: “Check-in closed” (ask the organizer to extend the window).
• Multi-day event with a daily schedule: “Day not enabled” when today is not an enabled day in the daily check-in schedule — verify the schedule with the organizer.

9. Kiosk self-service

Kiosk mode lets guests scan their own tickets without staff.

• Configure the idle timeout and input source (camera/keyboard) before enabling.
• Kiosk records the check-in method as “Kiosk scan”.
• Suited to high-volume events, but requires remote monitoring and on-site support when guests hit issues (cases 3–5).

10. Session expired

The login session is invalidated or expired — the staff member is kicked out of the session.

• Sign back in with credentials or a QR login code.
• Cached offline scans are preserved and will sync after re-login (on the same device).

11. Transient network errors vs input errors

The two error classes are handled differently — important to avoid getting stuck.

Error class	Examples	Handling
Transient	No response, transient server errors, server unreachable	Cache offline, show “Queued locally” / “Network error”, auto-sync on reconnect
Input / invalid-ticket	Session expired, invalid ticket, wrong-event ticket	Surface immediately, do not cache to avoid replaying invalid scans

12. Party size is wrong at the door (walk-in companions)

The guest arrives with more (or fewer) people than the ticket records — a walk-in companion event.

• If the organizer allowed door-side companion editing for the event, tap the party-size chip on the result card and set the correct number with the wheel — attaching companions to a guest already inside admits them immediately.
• Adjusting the count re-stamps the party’s check-in time, so the recorded admission time is the moment the door last touched the party.
• If the event does not allow door edits, escalate to the organizer, who can correct the count from the guest table (see Manage the guest list).
• Full details: Changing the party size at the door.

Quick lookups

Scan states

Full table of all 14 color states and their actions — see details.

Check-in overview

Back to the overview for the two roles and the main flow — see overview.