Microsoft Teams Phone: Error Code 484 Fix – Causes & Solutions

Microsoft Teams Phone Error Code 484 usually appears when the number sent toward Direct Routing does not arrive in a format that the next hop accepts. Microsoft maps this failure to Microsoft response code 560484 together with SIP 484, and the official description is Invalid number format. SBC rejected the call. That shifts the investigation toward number formatting, normalization, route patterns, translation rules, short extension behavior, and transfer logic rather than media quality or device setup. Microsoft also notes that some cases are simply invalid dialing, while some transfer scenarios can point to missing configuration in ByotOutUserForwarding. ^{[✅Source-1]}

Table of Contents

What Error Code 484 Means in Teams Phone

At the SIP layer, 484 means Address Incomplete. RFC 3261 defines it as a case where the server received a request with an incomplete Request-URI. When administrators investigate cases like this, they often compare the behavior with other documented Microsoft Teams phone system error codes to confirm whether the issue originates from numbering normalization, routing logic, or SBC translation rules. That is why this error often traces back to digits missing from the final string, a number that was normalized into the wrong target shape, or a route that expects a different numbering pattern. The symptom looks simple. The path behind it usually is not. ^{[✅Source-3]}

Layer	Value	Plain Meaning	What to Inspect First
Microsoft response code	560484	Invalid number format; SBC rejected the call	Direct Routing call record, destination pattern, transfer behavior
SIP response code	484	Address incomplete	Request-URI, normalized output, final dial string
User-facing symptom	Voice prompt or failed call	The number format is not accepted	Dialed number, copied number, short code, trunk prefix
Usual owner	Tenant or telephony admin	Dial plan, route, SBC, or translation issue	Effective dial plan and route-based translations

Where the Failure Usually Starts

Teams uses dial plans to translate numbers that users enter into a standardized format, typically E.164, before routing the call. That translation step matters because a user may dial a familiar local string while the route and SBC expect a fully normalized number. A number that looks fine to the caller can still be wrong for routing. ^{[✅Source-4]}

Dial Plan Normalization Did Not Produce the Expected Number

A familiar example is local or national dialing that omits the country code, area code, or an organization-specific access pattern. Short extensions, leading zeroes, copied phone numbers with extra characters, and mixed domestic versus international habits all fit here. If the final normalized result does not match what the voice route and SBC expect, the call can stop with 484.

Rule Order Changed the Outcome

Teams evaluates normalization rules from top to bottom and uses the first rule that matches. Microsoft also enforces a limit of 50 normalization rules in a dial plan. A broad rule placed too high can catch a number before a more precise rule ever sees it. Easy to miss, and very common after a tenant dial plan grows over time. ^{[✅Source-5]}

Voice Route or SBC Translation Expects Another Pattern

Even when the dial plan normalizes correctly, the outbound voice route or SBC can still expect another number shape. That happens when the tenant sends +E.164 but the SBC is configured for 10-digit or 4-digit routing, or when route priority and PSTN usage order steer the call into a pattern that does not fit the destination. A call that fails only for one country or one destination range often lands here. ^{[✅Source-6]}

Transfer and Forwarding Paths Need Their Own Review

When direct outbound dialing works but a transfer or forward fails with 484, check the logic used for the forwarded destination. In these cases, the number may be leaving the user context in a different format than the one tested in a normal outbound call. The caller thinks the target changed. Operationally, the number path changed.

What End Users Should Check First

E.164 allows a maximum of 15 digits, with a 1-to-3 digit country code. Microsoft’s globalization guidance also notes that the plus sign stands in for the international call prefix, while domestic dialing may involve a trunk prefix such as 0. Those details matter because many 484 cases start with a number that looks human-friendly but is not routing-friendly. ^{[✅Source-7]}

1. Dial the full external number, not the short form you use on another platform.
2. Remove labels, extra punctuation, copied text, and extension notes from the dial field.
3. If a 4-digit or 5-digit code fails, try the full assigned number for the same target.
4. If the failure happens only on transferred or forwarded calls, note that pattern before opening a ticket.
5. Capture the exact number dialed, the time, and whether the call was direct, transferred, or forwarded.

What Admins Should Verify in Order

For user-level troubleshooting, Microsoft points admins to Call analytics and Call Quality Dashboard in the Teams admin center. For Direct Routing pattern analysis, Microsoft Graph exposes a Direct Routing call log where each row maps to one call, and the API paginates after the first 1,000 entries with @odata.nextLink. That makes it practical to confirm whether 484 is isolated, country-specific, user-specific, or tied to one route. ^{[✅Source-8]}

1. Confirm the exact dialed string, destination country, call type, and whether the call was transferred or forwarded.
2. Review the failed call for CallEndSubReason 560484 and compare patterns by number range, user, site, and country.
3. Check the user’s effective dial plan, not only the tenant dial plan you think is assigned.
4. Test the dialed number against the effective dial plan before changing any route or SBC setting.
5. Inspect route priority, PSTN usage order, and the dialed number pattern on the voice route.
6. Inspect outbound translation rules on the SBC profile and confirm the final number shape that leaves Teams.
7. Verify the assigned phone number on users and resource accounts, especially when extensions are involved.
8. Retest the same call path that failed originally. A direct call retest does not fully validate a transfer failure.

Trigger Patterns That Often Lead to 484

Pattern	What Usually Happened	What to Check
Local PSTN number fails, full international number works	The local string was not normalized into the route’s expected format	Dial plan rules, usage location, country code handling
Short internal extension fails for an external target	No matching rule translated the short code into a routable destination	Extension normalization, SBC translation, assigned destination format
Direct dial works, transfer fails	The transferred destination used a different routing or translation path	Forwarding logic, route-based translation, transfer scenario settings
Only one country or carrier range fails	The route or SBC expects another pattern for that range	Voice route pattern, country-specific translations, downstream acceptance
Only one user or site fails	The effective dial plan or assigned number differs from expected	User policy assignment, service country rules, number assignment

Fix Paths That Match the Way 484 Usually Appears

When the Number Needs Cleaner Normalization

Microsoft recommends that normalization rules result in numbers that start with a plus sign, and the Teams admin center lets you test a dial plan directly. If the normalized number is still not what the SBC wants, Direct Routing customers can remove the plus later by using trunk translation rather than producing mixed output in the dial plan itself. That keeps the user-side number logic much easier to read and test. ^{[✅Source-9]}

• Use a narrow rule for short extensions before broader national rules.
• Normalize to +E.164 first.
• Test the exact string that failed in production.
• Retest the original call path after any rule change.

When the SBC Needs a Different Number Shape

Microsoft’s Direct Routing translation examples show why 4-digit and 10-digit behavior can diverge. Teams can normalize numbers one way while the SBC rewrites them again for outbound or inbound routing. Microsoft also states that the maximum total number of translation rules on the SBC side is 400. When the environment carries many legacy patterns, stale translation entries can quietly steer just one range into 484. ^{[✅Source-10]}

When Extensions Are Stored in the Assigned Number

Microsoft supports Direct Routing phone numbers with extensions in the form +1206555000;ext=1234 or 1206555000;ext=1234 on user or resource accounts. If the assigned number format and the route translation logic disagree, the call can fail even though the target object exists. This shows up often with auto attendants, resource accounts, and legacy PBX migration projects. ^{[✅Source-11]}

Numbers and Limits That Matter During Troubleshooting

Item	Value	Why It Matters for 484
Microsoft subreason	560484	Confirms the failure is tied to invalid number format and SBC rejection
SIP code	484	Confirms an incomplete or unusable address at SIP level
E.164 maximum length	15 digits	Helps validate copied and transformed numbers
Country code length	1 to 3 digits	Useful when a route fails only for one region
Normalization rule limit per dial plan	50 rules	Large rule sets raise the chance of overlap and wrong first-match behavior
Maximum Teams translation rules on SBC configuration	400 total	Legacy migrations can accumulate stale rules that affect only narrow patterns
Direct Routing log page size via Graph	1,000 entries before paging	Useful when trend analysis spans large call volumes

These values help turn a vague failed call into a shorter investigation. If the number is valid, the rule order is correct, and the route still rejects it, focus next on what the SBC expects to receive and what it actually receives. There is often a mismatch between those two views, not a random fault.

PowerShell Checks That Save Time

Microsoft provides cmdlets to retrieve a user’s effective tenant dial plan and to test normalization for the exact dialed number. Those two commands answer a very practical question: “What did Teams think this number should become before it hit routing?” Start there before editing live voice routes. ^{[✅Source-12]}

Get-CsEffectiveTenantDialPlan -Identity user@contoso.com

Test-CsEffectiveTenantDialPlan -DialedNumber 14255550199 -Identity user@contoso.com

If the test output does not match the number pattern that your route or SBC expects, fix that layer first. If the test output is correct, inspect the next translation step rather than rewriting the dial plan again. Change the smallest layer that explains the failure. Cleaner that way.

FAQ