When Microsoft Teams Phone Error Code 410 appears during a call, the useful clue is rarely the number alone. In Microsoft’s Direct Routing troubleshooting catalog, SIP 410 appears with three Microsoft subcodes — 531000, 531004, and 531005 — and each one points to a different repair path. Read the subcode first. Then test the path it names. [✅Source-1] Plain-English Reading 531000 usually points to SDP negotiation that is malformed or unsupported. 531004 points to ICE connectivity checks that could not build a media path. 531005 means the media path was up and then failed. Table of Contents How Error Code… Microsoft Teams Phone: Error Code 410 Fix – Meaning & Steps

Error Code 420 in Microsoft Teams Phone usually points to a SIP signaling mismatch inside Direct Routing, not a local desktop cache issue. Microsoft maps this failure to 420 Bad Extension and lists two practical combinations for it: 540420 and 560420. That split matters. One path often points to an unsupported required extension such as 100rel; the other often points to a header path that must be checked more carefully, including transfer-related signaling such as Replaces. [✅Source-1] If you start with a Teams reinstall, cache cleanup, or headset swap, you often lose time. For this code, start with the SIP… Microsoft Teams Phone: Error Code 420 Fix – Meaning & Workarounds

Error Code 422 in Microsoft Teams Phone usually points to a Direct Routing timer mismatch, not a user-side setting. In the Teams Phone scenario covered here, the code is commonly recorded as 540422 / 422 Session Interval Too Small, which means the offered Session-Expires value sits below what the far side accepts. Start with the SBC SIP profile, the timer values, and the refresh method before you touch policies, number assignment, or licensing. [✅Source-1] Read the Final SIP code, Final Microsoft subcode, and SIP phrase together. Compare Session-Expires and Min-SE on the Teams-facing trunk. Confirm the SBC refreshes longer calls… Microsoft Teams Phone: Error Code 422 Fix – Causes & Solutions

Microsoft Teams Phone Error Code 412 usually appears when an inbound Direct Routing call reaches Teams with a target number that cannot be parsed into a valid callee MRI (Messaging Resource Identifier). In Microsoft’s own mapping, this pattern is tied to Microsoft response code 510412 together with SIP 412, so the fastest repair path is to inspect the called number, its format, and the translation applied before the call lands in Teams. [✅Source-1] Focus first on the called number Not the Teams cache Look for Final SIP code 412. Match it with the Final Microsoft subcode. If the pair is… Microsoft Teams Phone: Error Code 412 Fix – Causes & Troubleshooting

Error Code 415 in Microsoft Teams Phone usually points to a Direct Routing signaling fault, not a generic desktop-app issue. Microsoft maps this failure to response code 540415 and describes it as a case where the SBC offer is missing or the request carries an unsupported media type. That changes the whole troubleshooting path: the first place to read is normally the SIP INVITE, its headers, and its body on the SBC side. [✅Source-1] Table of Contents SIP 415Meaning: The request body or offer is not accepted in its current form. 540415Microsoft Mapping: Missing SBC offer or unsupported media type.… Microsoft Teams Phone: Error Code 415 Fix – Causes & Solutions

Error Code 405 in Microsoft Teams Phone usually points to a method mismatch, not a random call failure. In SIP terms, 405 means Method Not Allowed: the request reached the other side, that side understood the request type, and then rejected the method being used. In real Teams Phone troubleshooting, this usually appears in Direct Routing, call transfer, SBC interoperability, or SIP device paths. Start there. [✅Source-1] Do not treat 405 as a generic “Teams calling is broken” message. Microsoft documents that the visible final SIP code can be generated either by the Session Border Controller or by a Microsoft… Microsoft Teams Phone: Error Code 405 Fix – Causes & Steps

When Microsoft Teams Phone shows Error Code 403, the service usually understands the call request and then refuses it for a defined reason. In plain terms, the block often comes from a policy setting, a license or Enterprise Voice gap, a voice route mismatch, or an SBC and Direct Routing validation issue. In SIP itself, 403 means the server understood the request but refused to fulfill it, so the next step is not guessing; it is finding the exact trigger behind that refusal. [✅Source-1] Do not treat every 403 as one generic permissions problem. Teams Phone maps this error to… Microsoft Teams Phone: Error Code 403 Fix – Causes & Troubleshooting

A 408 error in Microsoft Teams Phone becomes much easier to fix once you stop treating it as one single fault. Sometimes the timeout sits on the client path. Sometimes it sits between Microsoft and the Session Border Controller. Sometimes the downstream PSTN side answers too slowly. The detail that changes the fix is the response code paired with 408. Start Here Capture the exact Microsoft response code shown with 408. Confirm whether the call uses Direct Routing. Open one failed call and one successful call from the same trunk or region. Check whether the pattern is tied to one… Microsoft Teams Phone: Error Code 408 Fix – Causes & Solutions

When Microsoft Teams Phone Error Code 404 appears, the fault usually sits in the voice signaling path, not in Teams chat or file access. In Teams Phone work, this error is commonly tied to SIP 404: the platform, the SBC, or the PSTN path could not match the dialed target to the right user, resource account, or transfer leg. Wrong number format, and Teams never finds the destination. Shared base number without the expected extension, same story. Microsoft documents two practical Teams Phone 404 branches for troubleshooting: 10202 for a missing replacement call during transfer-related flows, and 511404 when reverse… Microsoft Teams Phone: Error Code 404 Fix – Meaning & Solutions

Error code 409 in Microsoft Teams Phone usually means the requested number change collides with the current state of that number. Administrators often compare this situation with other documented Microsoft Teams phone system error codes to determine whether the conflict comes from number ownership, provisioning state, or hybrid synchronization. In plain language, Teams already sees the number, the target account, or the management source as busy, assigned, pending, or controlled elsewhere. Most successful fixes start in three places: assignment status, activation state, and where the number is managed. Microsoft said Teams Phone passed 20 million PSTN users. At that scale,… Microsoft Teams Phone: Error Code 409 Fix – Causes & Resolutions

Microsoft Teams Phone Error Code 402 is not a generic desktop glitch. In a confirmed Direct Routing case, the pair that matters is Final SIP code 402 with Final Microsoft subcode 560402. Microsoft ties that pair to a failed call path that should be checked in call records, with special attention to the called number and the destination country or region. Read that first, then the repair path becomes much shorter. Start here: when the same user can place some PSTN calls but fails on a certain range, country, or route, carrier-side routing, SBC path selection, or voice routing deserves… Microsoft Teams Phone: Error Code 402 Fix – Meaning & Solutions

Error Code 400 in Microsoft Teams Phone is not a final diagnosis. It is a rejection code. Engineers often compare cases like this with other documented Microsoft Teams SIP and calling error codes to determine whether the failure belongs to device authentication, number normalization, or the Direct Routing SIP path. In real deployments, it usually shows up in one of two layers: the phone cannot finish an authentication request, or Direct Routing rejects a malformed or unsupported SIP request before the call settles. Same number, different failure path. Start Here Split the case first. If the user cannot sign in… Microsoft Teams Phone: Error Code 400 Fix – Causes & Solutions

Error Code 401 in Microsoft Teams Phone points to one thing first: the service did not accept the current authentication context. Engineers often compare this scenario with other documented Microsoft Teams calling and authentication error codes to determine whether the break sits in the user session, the voice configuration layer, or the call routing path. That can come from a stale client session, a user who is not fully voice-enabled, a SIP device challenge that never finishes, or a Direct Routing leg that fails before the call settles. Same number, different layer. Read the layer first, and the repair path… Microsoft Teams Phone: Error Code 401 Fix – Causes & Steps

Microsoft Teams serves over 320 million monthly active users [✅Source-1], and on Windows the desktop client relies on a brokered sign-in path that uses Primary Refresh Token (PRT), Web Account Manager, and Microsoft Entra token exchange. When Error Code 0xCAA90056 appears, the visible app is Teams, but the break is often lower in that chain. Installed, yes. Authenticated, no. [✅Source-2] On This Page What Usually Matters Most 0xCAA90056 usually points to a silent sign-in failure, not a chat, meeting, or channel problem. In plain terms, Teams asks Windows for a valid token, Windows tries to renew it quietly, and that… Microsoft Teams: Error Code 0xCAA90056 Fix – Meaning & Steps

If Microsoft Teams Error Code 0xCAA90057 appears during sign-in, start by treating it as a desktop authentication-path issue, not as a chat, meeting, or file-content problem. Teams uses modern authentication and single sign-on, so this error usually shows up when the local account state, cached identity data, saved credentials, device registration, or the Windows account broker is out of sync. [✅Source-1] What makes this error sticky is local state. Microsoft notes that Teams can cache general user information for up to three days, while some client-side data such as display name and phone number can stay cached for up to… Microsoft Teams: Error Code 0xCAA90057 Fix – Causes & Solutions

Microsoft Teams error code 0xCAA70007 usually shows up when the desktop client loses the connection it needs while it is finishing Microsoft 365 sign-in. This is not a random crash label. It points to an interrupted authentication path between the local Teams client, the Microsoft sign-in service, and the network controls sitting in the middle. Teams now serves over 320 million monthly active users, so the same code appears in home, school, and enterprise setups alike.[✅Source-1] A fast way to narrow it down is to split the problem into three cases: Teams desktop fails but Teams web works, Teams and… Microsoft Teams: Error Code 0xCAA70007 Fix – Causes & Solutions

Error code 0xCAA90014 in Microsoft Teams usually points to a sign-in token problem, not a chat or meeting feature problem. Teams often shows the symptom, while the real break sits lower in Microsoft Entra ID, federated authentication, cached credentials, Windows account state, or device registration. Fixing it gets much easier once those layers are separated. What the code means: Microsoft maps 0xCAA90014 to ERROR_ADAL_WSTRUST_REQUEST_SECURITYTOKEN_FAILED. In practice, that means the sign-in flow reached a WS-Trust or federated authentication step, the server returned a fault, and Teams could not obtain the assertion it needed. Microsoft also documents the decimal form as -894894060.… Microsoft Teams: Error Code 0xCAA90014 Fix – Causes & Solutions

When Microsoft Teams error code 0xCAA30194 appears, the desktop app usually fails during the sign-in and service connection path, not during chat or meeting rendering. Teams can often open the account prompt, then stop before the app finishes the Microsoft 365 handshake. That is why the most useful checks sit in cache state, app version, network reachability, Windows sign-in components, and tenant-side health—not in random cleanup. Table of Contents Desktop app fails, web app worksThis usually points to the local Teams client path, Windows sign-in components, or network handling on the device. Reinstall alone often misses the causeLeftover cache, account… Microsoft Teams: Error Code 0xCAA30194 Fix – Meaning & Steps

When Microsoft Teams shows 0xCAA5001C on Windows, the desktop app usually breaks before it completes the Microsoft Entra sign-in flow. Microsoft documents this code as a token broker operation failed condition tied to the Windows authentication layer and the Microsoft.AAD.BrokerPlugin path, not to Teams chat data itself. [✅Source-1] That changes the fix order. Teams on Windows uses modern authentication and Web Account Manager, so a desktop-only failure often points to a local identity problem: stale account binding, broken cache, unhealthy device registration, or broker permissions inside the user profile. Often, the app is only the messenger. [✅Source-2] Desktop app fails,… Microsoft Teams: Error Code 0xCAA5001C Fix – Causes & Troubleshooting

Microsoft Teams Error Code 0xCAA90018 usually appears when the Windows sign-in identity on the device does not line up with the Microsoft 365 account that Teams expects to use. Microsoft’s own status table describes this code as a credential mismatch, not a generic connectivity failure. That detail matters, because the fix is rarely “reinstall and hope.” It usually sits in account selection, saved credentials, Windows account binding, or old Teams cache data. Microsoft also says Teams serves over 320 million monthly active users, so these identity-flow issues surface in many real Windows environments, especially on devices that switch between personal… Microsoft Teams: Error Code 0xCAA90018 Fix – Causes & Troubleshooting

Microsoft Teams error code 0xCAA82EE2 means the sign-in request timed out. That detail matters. This code usually points away from a simple password typo and toward a path problem between the Teams client and the Microsoft 365 sign-in flow: network reachability, proxy handling, firewall rules, stale local app data, or a device-side sign-in path that never finishes cleanly. Timeout code, yes; random code, no. [✅Source-1] What usually broke firstThe Teams app started authentication, waited for the reply, and hit a timeout before the flow came back. The fastest split testCompare the desktop app with Teams on the web. That one… Microsoft Teams: Error Code 0xCAA82EE2 Fix – Causes & Solutions

When Microsoft Teams shows Error Code 0xCAA20004, the sign-in request reached the identity layer but still failed at the approval or policy stage. Microsoft maps this code to a request that must be approved by a resource owner or authorization server, which is why the issue usually points to Microsoft Entra policy enforcement rather than a plain password typo. Correct password, yet blocked. That can happen here. [✅Source-1] Teams runs at very large scale, with Microsoft stating that the platform serves over 320 million monthly active users. On managed tenants, that scale brings many access rules, device states, and tenant… Microsoft Teams: Error Code 0xCAA20004 Fix – Meaning & Steps

Microsoft Teams error code 0xCAA20003 appears during sign-in, not during chat, meetings, or calling. Microsoft lists it as an authorization problem, and the first check is surprisingly simple: make sure the device date and time are correct, because a bad clock can block access to secure sites over HTTPS. [✅Source-1] In practice, this error usually comes from one of four places: time drift, stale desktop app state, Windows or Microsoft 365 identity mismatch, or a managed-device / federation issue. Start with the device. Move up to account and tenant checks only if the local steps do not change the result.… Microsoft Teams: Error Code 0xCAA20003 Fix – Meaning & Solutions

Microsoft Teams error code 0xCAA70004 usually appears during sign-in, not during normal chat or meeting use. In plain language, Teams cannot reach part of the Microsoft identity path it needs to finish authentication. Microsoft’s own support table describes this code as a case where the server or proxy was not found, and it also notes that a misconfigured proxy or a traffic inspection tool such as Fiddler can trigger it. [✅Source-1] Table of Contents Most common direction:Proxy discovery, TLS inspection, or a blocked sign-in route. High-value clue:If Word, Outlook, or OneDrive also fail to sign in, move beyond Teams-only fixes.… Microsoft Teams: Error Code 0xCAA70004 Fix – Causes & Workarounds