Why Didn't My Door Lock Code Work?

Why Didn't My Door Lock Code Work?

When a guest texts you saying the code isn't working, you have about two minutes before the situation turns into a refund request. This article is the fast triage: the five causes that account for almost every "code not working" incident, in the order to check them.

Fast Triage (90 seconds)

Before reading the details below, run this quick pass:

1. Open Staykey, find the stay, confirm the code. Is the code the guest is entering the same one shown on the stay's page?
2. Check the lock's status. In the property's device list, does the lock show "online" with a recent last-seen?
3. Check the date. Is it currently inside the stay's check-in-to-check-out window (plus the grace period)?
4. Check the battery. The lock's device page shows battery level. Under 20% is when most locks start behaving weirdly.
5. Check the lock's event log. Every major lock type logs the last several code entries. Did the guest's attempt show up as "wrong code" or nothing at all?

If steps 1–5 all look fine and the code still isn't working, jump to The nuclear option at the bottom of this article.

The Five Most Common Causes

1. The Guest Is Using the Wrong Code

More common than anyone likes to admit. The guest may be:

• Looking at a code from a previous booking at a different listing
• Reading the Wi-Fi password as the door code (it happens)
• Using the code for the building door instead of the unit door (for multi-door properties)
• Missing a digit because they're reading from a tiny preview in a message thread

Fix: Ask the guest to open the durable Staykey guest link you included in their Airbnb message. That link always shows the current active code in a big readable format. If they can't find the link, resend it in the Airbnb thread.

2. The Lock Is Offline

If the lock can't talk to Home Assistant, Staykey can't push or update codes. Often this just means the lock pushed an old code that has since rotated out, or the current stay's code never got written to the lock.

How to tell: In Staykey's device page for the lock, the "last seen" timestamp is more than an hour old, or the device is flagged offline.

Fix:

• If it's a Z-Wave or Matter lock, the hub is usually the issue — reboot the Home Assistant hub
• If it's a Wi-Fi lock, the property's Wi-Fi is usually the issue — reboot the router
• After the lock reconnects, wait a minute and then open the stay in Staykey and click Re-push code in the stay's actions menu

See device not responding for the full rundown.

3. The Code Hasn't Activated Yet

Staykey programs codes to be active only during the stay's valid window (typically from check-in day at a configurable time through check-out + 1 day). If the guest is trying to enter on check-in day before the activation time — for example, a guest arriving at 11 a.m. when check-in is at 3 p.m. — the code will be rejected by the lock as not-yet-valid.

How to tell: The stay's start date is today, and the current time is before the code's activation time. The stay's page in Staykey shows the configured activation window.

Fix:

• If the guest is approved for early check-in, open the stay and click Extend code start to activate it early
• Otherwise, let the guest know the code will start working at 3 p.m. (or whatever your configured time is)

4. The Lock's Keypad Slots Are Full

Many smart locks have a fixed number of code slots (often 20–30). If you've accumulated many historical codes that weren't cleaned up, Staykey may not have been able to write the new code.

How to tell: The stay in Staykey shows a warning like "Code could not be written — lock full", or the lock's own log shows the slot wasn't updated.

Fix:

• Open the lock in Staykey
• Click Clean up unused codes
• Once slots are freed, re-push the stay's code

This is more common on Kwikset 910/914 and older Schlage BE469 locks. Newer Home Assistant-compatible locks typically handle this automatically.

5. The Battery Is Too Low

Below about 15–20%, most smart locks start failing intermittently — particularly on cold mornings or after heavy use. The lock may accept the code, beep, and fail to retract the bolt. Guests read this as "the code didn't work."

How to tell: The device page shows a low-battery warning, or the lock has a battery-saver mode flag enabled.

Fix:

• If the guest is already at the door, have them press the keypad, wait a few seconds, press the unlock button again (some locks need two presses at low battery)
• If the guest is not yet at the door and you can get there, swap batteries before they arrive
• Long-term, set up battery-alert notifications at 30% so this is never a surprise

Platform-Specific Gotchas

• Kwikset 910/914: Sometimes the lock responds to the wrong slot number after a Home Assistant restart. Re-pushing the code fixes it.
• Schlage BE469: The keypad deactivates for 30 seconds after 3 wrong attempts. If the guest mis-entered a couple of times, they just need to wait.
• August (Wi-Fi): August locks can take 10–30 seconds to accept a new code after it's pushed. A guest arriving in the first minute may see "invalid code" and then have it work on the next attempt.
• Yale Assure: The Yale keypad needs the # key pressed after the code. Non-obvious, worth adding to your house guide.

The Nuclear Option

If nothing above diagnoses the issue, the fastest path for the guest is:

1. Remote unlock. Most Home Assistant-connected locks expose a remote unlock from Staykey. Open the stay, click the lock, click Unlock now. This bypasses the code entirely and lets the guest in.
2. Backup method. If you have a lockbox or a keyed deadbolt override, walk the guest through it while you troubleshoot.
3. After the guest is inside, file the root-cause investigation with the full event log attached.

Once the immediate issue is resolved, audit the lock and the stay to make sure the next guest doesn't hit the same wall.

Still can't figure it out? Contact support with the stay ID, the lock model, and a screenshot of the lock's event log. We can usually identify the root cause within an hour.