Smart Home Website
Tip

Smart Locks and Guest Access: Who Gets In

Security & Privacy Smart Home Website Smart Home Website #security#privacy

A smart lock turns access into a credential you can send, schedule, and revoke. Here's how to give guests a key without giving away the house.

Smart Locks and Guest Access: Who Gets In

Prices in this article are typical U.S. retail, checked October 2026.

Section 1: Why is the key the weak point? (Introduction)

Guest access is the weak point in a smart lock: a code shared once can live forever. Use temporary codes, set start and end times, review who has access, and revoke at the end of the stay, not when you remember.

A physical key is a copy of your front door that you hand to someone and then hope to get back. Cleaners keep them, contractors lose them, guests forget them, and the only real remedy is a locksmith and a new cylinder. The key is the oldest access-control system in the house, and it is the one with the worst revocation story. A lost key is a locksmith bill and a day of inconvenience.

A smart lock changes the unit of access from an object to a credential: a code, a phone, a fingerprint, or a temporary key you send through an app. That makes giving access easier and, more importantly, makes taking it back possible. It also introduces new failure modes — dead batteries, dead phones, and a cloud service that decides your schedule is optional.

This guide covers the three ways a smart lock lets someone in, how to give access to a guest, cleaner, or contractor, how to revoke it cleanly, and what to do when the lock or the network fails. For the wider security picture, start with the Security & Privacy hub.

Section 2: Which access model fits each person?

Every smart lock combines some of these. The right mix depends on who needs in and how often.

Model What it is Good for Weak point
Physical key The original cylinder Backup, family, power loss Copies, loss, rekeying
Code / keypad A PIN entered on the lock Guests, cleaners, contractors Shared codes, shoulder surfing
Phone / app A digital key, auto-unlock, remote unlock The household, frequent guests Battery, Bluetooth, account access

The hardware comes in three shapes. A full deadbolt replacement, like Schlage’s Encode, changes the exterior hardware and the cylinder; it looks like a normal lock and needs the landlord’s blessing in a rental. A retrofit like August’s attaches to the inside of the existing deadbolt and keeps the original exterior and keys. A lever or mortise lock replaces a different kind of hardware entirely and is a bigger job. The Smart Locks 101 guide covers the mechanics.

The physical key

Keep it. Every smart lock worth buying still has a key cylinder, and the key is the answer to a dead battery, a failed radio, and a forgotten code. August’s retrofit lock attaches to the inside of the existing deadbolt and keeps the original keys, which is why it works in rentals and for family members who do not want an app.

Codes and keypads

A keypad is the most useful guest credential: it needs no app, no account, and no phone battery. Schlage’s Encode deadbolt supports up to 100 access codes with schedules and a history log, which is enough for a household, a cleaner, a dog walker, and a contractor without reusing a single code.

The weakness is human. A code can be shared, watched, or written on a sticky note. Use a different code for each person, and change the ones that matter when the relationship ends. For the phone-based alternative, see What Is Aliro?.

Phone keys and remote unlock

A phone key is convenient for the household: August’s Guest Keys let you send access through the app, and the activity feed shows who came and went. Remote unlock is useful when someone arrives early and you are not home.

The weakness is the account. Anyone with your login can unlock the door, which is why the lock account deserves the same treatment as email: a unique password, multi-factor authentication, and a review of who else has access.

Fingerprints deserve a note of their own: they are fast and impossible to share, but they are also impossible to revoke remotely. Use them for the household, and keep codes for everyone whose access might need to end without a conversation.

Section 3: How long should a guest’s access last?

The right method depends on how long the person needs in.

Family and long-term household

Give each adult their own code or app key, not a shared one. Individual credentials are what make the history log useful and revocation clean. If the lock supports it, use a fingerprint for the people who live there and a code for everyone else.

Cleaners, dog walkers, contractors

These are the people a physical key was always worst for: they need regular access, they are not family, and the relationship can end without warning. A scheduled code is the right tool, and a different code per person is the right habit.

Use a scheduled code with a start and end time, not a permanent one. Schlage’s app supports scheduled codes, and the lock keeps a history of when each code was used. Set the code to expire the day after the job, and verify that it actually stopped working.

A contractor doing a one-day job is a different case. Do not give a code you will forget to delete; meet them, use a lockbox with a code you change afterward, or unlock remotely when they arrive. The fewer permanent credentials in the world, the better.

One important caveat, from Schlage’s own support documentation: scheduled codes are stored in the cloud, so they will not work if the lock goes offline, and only the codes that were active when the lock lost Wi-Fi continue to function. That is fine for a cleaner; it is not a security boundary you should rely on for a contractor you do not trust.

Short-stay guests

A one-time or short-window code is the right answer for a guest staying a weekend. For a rental property, a unique code per stay is the standard, and it should expire at checkout. Put the expiry in the booking checklist, not in your memory. If the lock supports it, generate the code remotely and send it through the booking platform rather than a text message that lives forever.

The fallback

Leave a physical key with a trusted neighbor, not under the mat. The smart lock is the convenience layer; the key is the emergency layer. The fail-safes guide makes the same argument for the rest of the house.

Section 4: How and when do you revoke access?

Revocation is the entire reason to own a smart lock, and it is the step people skip.

  • Delete the code, not just the person’s name. In most apps, removing a user removes their app access but may leave a keypad code active. Check both.
  • Change the master code if it was ever shared or written down.
  • Review the history. Most locks log every code and app unlock, along with battery warnings and lockout events. A code used at 2 a.m. by someone who should be asleep is worth a conversation. Screenshot the log before you clear it if you may need it later.
  • Rekey if a physical key is lost. A smart lock does not make the cylinder disappear.
  • Remove the app user and revoke the share link. If you sent a guest key, revoke it in the app rather than waiting for it to expire.

A revocation checklist, in order:

  1. Delete the keypad code.
  2. Remove the app user or revoke the guest key.
  3. Change the master or programming code if it was shared.
  4. Check the history for use after the revocation.
  5. Rekey the cylinder if a physical key is unaccounted for.

Test revocation the way you test a smoke alarm: give a code, use it, delete it, and try it again. If it still works, you deleted the wrong thing.

Section 5: What do you do when the lock fails?

A smart lock fails in predictable ways, and each has a manual answer.

Dead battery. The lock warns for weeks before it dies, and the key still works. Some models have jump terminals for a 9-volt battery; check yours before you need it. Do not ignore the warning because the app still shows the lock online.

Wi-Fi or hub down. Keypad codes stored on the lock still work; the app and remote unlock do not. This is the argument for a keypad even if you mostly use your phone. The fail-safes guide covers the broader outage plan.

Dead phone. A code or a key is the backup. A household that relies entirely on phones is one dead battery away from a locksmith.

Lockout. Know where the spare key is and who has it. A lockbox with a combination is a reasonable backup for a rental; a key under the mat is not. A lockbox code should be changed after every guest who used it, and the spare key should be labeled so it is not mistaken for a dead one.

A lock that is offline for days. A lock with a keypad still opens with codes already stored on it, but scheduling and remote unlock stop. If the lock is offline because the Wi-Fi is down, the fix is the network, not the lock. If it is offline because the hub died, the keypad is the bridge until you replace the hub.

False auto-unlock. Some locks unlock when the phone approaches. That is convenient and occasionally wrong — a phone inside the house can unlock the door for someone outside. If that bothers you, turn auto-unlock off and use a code.

The lock and the camera disagree. A camera can show a person at the door while the lock says it never opened, or the reverse. Trust the lock’s event log for access and the camera for identity; neither is a complete record on its own.

The guest who was never removed. The most common failure is not technical. Review the user list quarterly, the same way you review camera sharing.

Section 6: What is the three-step access plan? (Conclusion)

  1. Pick the install you can reverse. A retrofit like August’s Wi-Fi Smart Lock at $199.99 keeps the existing deadbolt and keys; a full replacement changes the hardware. Renters should read the renting guide first.
  2. Give each person their own credential. A code for the cleaner with an end date, an app key for family, a fingerprint for the household, and a physical key with a neighbor.
  3. Test revocation and failure. Delete a code and try it. Turn off the Wi-Fi and use the keypad. Let the battery run low once, on purpose, and confirm the warning is real. Then review the access list quarterly, the way you would a bank statement.

A realistic budget: about $200 for a retrofit lock, $30 for a lockbox, and the cost of a spare key. That is the whole access system for most homes, and it is less than a single rekey after a lost key.

Some homes should skip the category. If you rent and the lease forbids changing the lock, a keypad lockbox is the compromise. If you live alone and never have guests, a good deadbolt and a key with a neighbor may be all you need. And if you are not going to review the user list, a smart lock just adds a digital copy of the same problem.

A smart lock is not a better key. It is a better access list: one you can read, edit, and audit. The value is not the app; it is knowing exactly who can get in, and being able to change your mind. If you never read the list, you have paid for a key with a battery.

Where to buy

Smart locks on Amazon

Opens an Amazon search. As an Amazon Associate, we earn from qualifying purchases. No product in this guide was supplied or tested by a manufacturer.

Sources