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Thread credentials and multiple Thread networks: how to share, sync and combine them for Matter

Thread credentials are the keys a device needs to join a particular Thread network — Home Assistant compares them to a Wi-Fi password. Your phone normally keeps them for you — Apple's developer docs say apps store them in iCloud Keychain, and Android Help says Google stores them in your Google Account. Border routers from different brands can each form their own network, which is why a home can end up with several. The Thread Group says devices on separate networks still work together over IP, while Home Assistant and SmartThings document ways to join one network (SmartThings' QR code / one-time passcode route needs a compatible Thread 1.4 border router on the other side).

What Thread credentials are

Google's Thread Network SDK page defines Thread network credentials as a "binary blob of Thread TLVs" that encodes the Thread network name, network key and other properties a device needs to join a given Thread network. In practice, that means credentials are a bundle of technical values, not a single password you'd memorise. Home Assistant's Thread integration tracks the different Thread networks in your home and stores their credentials, which it describes as "similar to a Wi-Fi password".

The Thread 1.4 white paper explains that the network key is not user-generated at all, and the commissioning credential is often not shown to users — the point is to keep onboarding simple and secure. When you pair a Thread device, Home Assistant says your phone connects to the device over Bluetooth LE, shares the Thread network credentials, and the device then joins the Thread mesh. Matter and Apple HomeKit handle those credentials; Thread by itself is just the communication layer. For more on that split, see what Matter is and how it relates to Thread.

Thread credentials at a glance

Each row below names its source, and the platform details follow in the next sections.

The table is a summary of the sources cited throughout this page. Where a platform's credential handling is described in developer documentation rather than a consumer settings page, that's noted in the relevant section below.

Why you can end up with several Thread networks

Home Assistant's Thread integration docs put it plainly: today, each vendor forms its own Thread network when you start using their products. You can end up with a Home Assistant, an Apple and a Google Thread network in the same home, all using different credentials. Home Assistant discovers all the border routers on your network because they send mDNS/DNS-SD announcements, but those local announcements don't contain the network credentials — that's why you can see a network listed without being able to use it. The configuration of border routers isn't part of the Thread standard, so Google and Apple border routers are set up and configured by their own ecosystems.

The Thread Group's 2023-08-24 post notes that because border router functionality can be built into smart speakers and TVs, a typical smart home will likely have several border routers. If those border routers don't share credentials, each forms its own Thread mesh network. The Thread 1.4 white paper adds that without credentials, a new border router would typically form an entirely new network, and that fragmentation could weaken overall mesh resilience. Thread is common among Matter products: 59 of the 106 products MatterCheck tracks use Thread for Matter. For which devices act as border routers, see Matter hubs and Thread border routers.

Do separate Thread networks stop Matter devices working together?

Not according to the Thread Group. Its 2023-08-24 post says that thanks to Thread's IP foundation, devices on different Thread networks can still "see" and work with each other, and with anything else on the broader network. The Thread network is independent of a particular Matter ecosystem or fabric. The Thread Group says most end users would not see a practical issue with having multiple Thread meshes in their homes.

Home Assistant gives the other side: devices can't roam between separate Thread networks, and "in theory" joining all networks into one would create a denser mesh with better RF coverage, better link quality and lower latency. eero says syncing credentials helps eero and supported Amazon products merge into a single shared Thread mesh to improve range and reliability, and SmartThings frames unification as a way to have all border routers work together. In short, the Thread Group says separate networks still work together, while Home Assistant and eero describe a single network as better for coverage, range or reliability. If you've shared a single device across platforms, that's a separate Matter multi-admin question — see sharing one Matter device with several platforms.

The preferred network: which Thread network your phone uses

Android phones and iPhones keep a "preferred" set of Thread credentials that apps can request with your consent. Google's codelab says the first border router added to Google Play services storage determines the preferred credentials for that Android device, and those credentials persist even if that first border router is later excluded. Android devices sync with Google border routers automatically, but only when the border router is paired with a single user or two users in the same structure. Google's SDK page tells border-router app developers to try the preferred credentials before creating a new network, so that Thread devices end up on a single network when possible.

Apple's developer documentation says storing credentials marks a network as preferred in iCloud Keychain, and retrieving preferred credentials requires user consent. Multiple border routers on the preferred network strengthen communication and improve resiliency. Home Assistant notes that when adding Matter devices through its companion apps, the preferred network of the mobile device is used, and that Home Assistant's own preferred-network function isn't completely implemented yet. These Apple and Google pages are written for developers of border-router apps, not as consumer how-tos.

Where each platform keeps Thread credentials

The table below summarises credential storage per platform. The subsections after it give the source-level detail.

Apple Home

Apple's developer documentation says Thread network credentials are stored in iCloud Keychain, where the system manages and protects them. Storing credentials marks the network as preferred. Apple Support 102135 says Thread accessories need a Thread-enabled home hub such as Apple TV 4K, HomePod (2nd generation), HomePod mini or a compatible third-party border router; Thread-enabled iPhones running iOS 18 can pair and manage Thread accessories locally, which may require an update from the accessory maker. Apple Support 102557 lists turning on iCloud Keychain and two-factor authentication among its steps for when a home hub isn't working as expected. The sources here don't give a consumer menu path for viewing Thread credentials in the Home app — Apple's credential pages are developer documentation.

Google Home and Android

Android Help says a Thread credential is created when you connect your Android device to a Thread network, and Google stores it securely in your Google Account. The consumer toggle is Settings > Connected devices > Connection preferences > Thread, then Use Thread. Turning Thread off leaves the stored credentials in place. Android Help also says your Android device can join an existing Thread network even if you don't have a dedicated Thread border router at home. Google TV Help says Google TV Streamer (4K) can create or join a Thread network and stores credentials in your Google Account; its Thread network switch is under Network and Internet. Google's SDK page is developer documentation, last updated 2022-10-13.

Alexa and eero

Amazon's Alexa developer page says Thread-enabled Echo devices act as border routers to provision and secure Thread networks, and that Echo and eero border routers support Thread version 1.1 or 1.3. With the customer's permission, a smart home add-on can access credentials through the Credential Locker API. eero's support article says linking your Amazon account can share Thread network identifiers, passwords and keys, and that syncing helps eero and supported Echo devices merge into a single shared Thread mesh. You can turn credential syncing off in the eero app, and delete stored credentials via Amazon's Manage Your Content and Devices. These are eero's statements about eero and Amazon products only.

Home Assistant: sync, import and choose a preferred network

Home Assistant's Thread page is under Settings > Connectivity > Thread. It lists all discovered border routers grouped by network. You can only set a network as preferred if Home Assistant knows its credentials, and Home Assistant says the preferred network function isn't completely implemented yet — when adding Matter devices through the companion apps, the phone's preferred network is used. Its Matter docs add that using a third-party border router such as a Nest Hub (2nd Gen) or HomePod mini doesn't mean you have to add your devices to those ecosystems: Home Assistant only uses them to reach the Thread radio network, and the border router passes the encrypted data along without being able to read it.

Making Home Assistant your first Thread network

Install the OpenThread Border Router app. Home Assistant Core 2023.3 and newer configures it automatically. If there are no other Thread networks yet, Home Assistant creates a network named ha-thread-xxxx, where the last four digits are a network-specific identifier. Check that it's marked as the preferred network, then share credentials to your phone:

1. On Android: in the Companion app, go to Settings > Companion app > Troubleshooting, then select Sync Thread credentials. You should see "Added network from Home Assistant to this device".
2. On iPhone: in the Companion app, go to Settings > Connectivity > Thread, then select Send credentials to phone.

Joining an existing Google or Apple Thread network

Home Assistant's prerequisite is an Android phone for a Google Thread network, or an iPhone for an Apple Thread network. Home Assistant also says the phone must be on the same Wi-Fi network as the Google border router (the steps are very similar for an Apple network with an iPhone). Then:

1. In the Companion app, go to Settings > Connectivity > Thread.
2. Select Send credentials to Home Assistant. On Android you should see "Imported credential".
3. Refresh the screen, then select Make preferred network.
4. Install the OpenThread Border Router app. It joins the preferred network only if it doesn't already have a Thread network. With a multiprotocol adapter, the preferred network must use the same channel, otherwise the border router creates a new network.

Adapters and migration

Home Assistant says your Thread network is managed by Home Assistant and is not stored on the adapter, so migrating to a new adapter means Home Assistant starts using the new radio instead of the old one. The OpenThread Border Router app docs list compatible radios including Home Assistant Yellow, Connect ZBT-1 and Connect ZBT-2. For the full Home Assistant Matter setup, see Home Assistant's Matter support.

SmartThings: Thread network unification

SmartThings announced on 2025-10-01 that it supports two-way Thread network unification. A new SmartThings hub can join an existing Thread network from another ecosystem, or a third-party border router can join the SmartThings network. A new Manage Thread Network menu in the SmartThings hub interface guides you through it:

• Join another network: join via saved Thread credentials in the mobile OS credential locker, or by scanning a QR code or entering a one-time passcode from a third-party app with a compatible Thread 1.4 border router in sharing mode.
• Share SmartThings network: generates a QR code and a one-time passcode that a third-party app can use to join its border router to the SmartThings network.

SmartThings said that at launch in Q3 2025 the feature would be available on select hubs, including the Aeotec Smart Home Hub and Aeotec Smart Home Hub 2, with more to follow, and that users would need hub firmware 0.58.x and SmartThings app 1.7.37.x (iOS) or 1.8.37.x (Android). SmartThings says full benefits depend on compatible Thread 1.4 border routers across ecosystems, and third parties may update on their own timelines. See SmartThings' Matter support for the broader picture.

Thread 1.4 credential sharing: the one-time passcode

The Thread Group announced Thread 1.4 on 2024-09-04. The Thread Group says that with 1.4 an updated device or border router joins the existing Thread network instead of creating a new one, and users can add a 1.4-updated Matter device to any existing Thread network connected by a Thread 1.4 border router. The same post says Thread over Infrastructure lets border routers use Wi-Fi and Ethernet to extend the mesh.

The Thread 1.4 white paper compares credential sharing to the "forgot my password" option many websites offer, and says it's only needed in exceptional cases where the credentials aren't available. The user starts sharing on the existing border router with a vendor-specific authentication step, and the border router presents a passcode as a QR code and/or a nine-digit numeric code. The passcode is short-lived and single-use, and the extracted credentials can then be stored on the phone for future onboarding. No Apple, Google or Amazon page in this guide says their border routers support Thread 1.4 credential sharing; Amazon's developer page lists Thread 1.1 or 1.3 for Echo and eero border routers.

Before you combine Thread networks: what to check

1. See which networks you already have. Home Assistant's Thread page lists all border routers grouped by network, so you can see how many separate Thread networks exist in your home.
2. Decide which network to keep. Home Assistant says if you have both Google and Apple Thread networks, decide which one you want to add the Home Assistant border router to.
3. Use the matching phone. Home Assistant's prerequisite is an Android phone for a Google Thread network and an iPhone for an Apple Thread network.
4. Keep the phone on the same Wi-Fi as the border router. Home Assistant lists this in its steps, and Android Help's troubleshooting says to verify the border router is on and connected to the same Wi-Fi network.
5. For SmartThings, check versions. The SmartThings blog says unification needs hub firmware 0.58.x, specific app versions, and a compatible Thread 1.4 border router on the other side.
6. For eero and Echo, credential sync is the mechanism. eero says syncing helps eero and supported Amazon products merge into a single shared Thread mesh, and it can be turned off in the eero app.
7. Expect possible re-adding after a channel change. Home Assistant warns that some Thread devices might not move to a new channel automatically and may need adding again.

Thread networks also sit on top of your home IP network, so IPv6, VLANs and mDNS settings matter too — see home network settings for Matter.

Thread channels and other changes that can strand devices

Home Assistant notes that Thread uses 2.4 GHz, and Thread channels 11 through 24 can overlap with common Wi-Fi channels like 1, 6 and 11, causing interference. Some Thread devices might not move to a new channel automatically, and you might need to add them again before they show up. You can only undo a channel change by changing the channel again. The Thread Group's Thread 1.4 announcement says Thread over Infrastructure lets border routers use Wi-Fi and Ethernet to extend the mesh, as the Thread Group's own description of the feature. If a device has already gone offline, see Matter devices that go offline.

Frequently asked questions

What are Thread credentials?

Thread credentials are the technical values a device needs to join a specific Thread network. Google defines them as a binary blob encoding the network name, network key and other properties. Home Assistant compares them to a Wi-Fi password, and the Thread 1.4 white paper says the network key is not user-generated and the commissioning credential is often not shown to users.

Where are Thread credentials stored on my phone?

Apple's developer documentation says apps store Thread credentials in iCloud Keychain. Google stores them in your Google Account, according to Android Help. Both platforms keep a preferred set of credentials that apps can request with your consent.

How do I sync Thread credentials to Home Assistant?

In the Home Assistant Companion app, go to Settings > Connectivity > Thread and select Send credentials to Home Assistant. On Android you should see "Imported credential"; then refresh and select Make preferred network. Use an Android phone for a Google network and an iPhone for an Apple network. To send Home Assistant's own network to an Android phone instead, Home Assistant uses Sync Thread credentials in the Companion app's troubleshooting settings.

What is a preferred Thread network?

The preferred network is the set of Thread credentials your phone uses by default when adding new Thread devices. Google's codelab says the first border router added to Google Play services storage determines it, and Apple says storing credentials marks a network as preferred in iCloud Keychain.

Should I merge my Thread networks?

It's optional. The Thread Group says devices on separate networks still work together over IP, and most users won't see a practical issue. Home Assistant says one network would "in theory" give a denser mesh with better coverage and lower latency. Neither says merging is required.

Can Apple, Google and Amazon Thread networks be combined?

Home Assistant can join an existing Google or Apple network by importing credentials from the matching phone. SmartThings' 2025-10-01 unification supports joining or sharing with compatible Thread 1.4 border routers. eero says credential syncing helps eero and supported Amazon products merge into a single shared mesh. No source here gives a direct Apple-to-Google or Apple-to-Amazon merge path.

Is Thread the same as Matter?

No. Thread is the networking layer — routing, commissioning and security — while Matter is the application layer that controls devices. Home Assistant says Thread by itself does not allow controlling devices, and the Thread Group says Thread addresses the networking layer while the application layer runs on top. See Thread vs Wi-Fi for Matter for the practical differences.

More MatterCheck guides

• Matter hubs and Thread border routers — which devices create and manage Thread networks.
• Thread vs Wi-Fi for Matter — how the two transports compare in practice.
• Home network settings for Matter — IPv6, VLANs and mDNS requirements.
• How to add a Matter device — the pairing flow from start to finish.
• Matter devices that won't pair — troubleshooting commissioning failures.
• Matter devices that go offline — what to check when a device drops.
• Sharing one Matter device with several platforms — multi-admin explained.
• What Matter is — the smart home standard in plain terms.
• Matter platform comparison — Apple Home, Google Home, Alexa, SmartThings and Home Assistant side by side.
• Matter on TVs: TV hubs and Matter Casting — which TVs and streamers are Matter hubs and what Matter Casting is.
• Matter on Hubitat, Homey and openHAB — which Hubitat, Homey and openHAB models support Matter, Thread and bridging.

How we checked

Pages fetched 2026-10-20 — Home Assistant's Thread and Matter docs (2026.10.2) and its OpenThread Border Router app docs; the Thread Group's 2023-08-24 post on multiple Thread networks, its 2024-09-04 Thread 1.4 announcement, the Thread 1.4 features white paper (September 2024) and its FAQ; Google's Thread Network SDK page (last updated 2022-10-13), Thread credentials codelab, Android Help 16335330, and Google TV Help 15178609; Apple's ThreadNetwork developer articles on configuring a border router and managing credentials, and Apple Support 102135 (published 2026-05-07) and 102557 (published 2025-09-15); Amazon's Alexa developer page on Thread; eero's account-linking article; and the SmartThings blog post of 2025-10-01. The Thread product count comes from MatterCheck's own data. Developer pages describe how apps handle credentials, not consumer menus, and support pages change. See how MatterCheck works.

Last reviewed 2026-10-20. If your border router's app says something different, follow the maker's own instructions.