Translate phone numbers for Direct Routing

Publisher

Microsoft

URL

https://learn.microsoft.com/en-us/microsoftteams/direct-routing-translate-numbers

Published

2026-09-10

Updated

unknown

Accessed

2026-09-21

HTTP status

200

License

Microsoft Learn terms of use; no-redistribution; short excerpts and locators only

Source notes citing this source

• Microsoft's example shows an inbound translation rule on the SBC profile (pattern ^(\d{4})$ to +1206555$1) that expands a four-digit called number arriving from the SBC into the E.164 number assigned to the Teams user. in context
• To avoid double normalisation, Microsoft recommends that Direct Routing customers normalise numbers to include a '+' in dial plans and then remove the '+' with a route-based translation rule if the SBC needs it. in context
• A tenant can have at most 400 translation rules in total; a pattern can be at most 1024 symbols and a translation at most 256. in context
• Direct Routing number translation rules are attached per SBC through New- or Set-CsOnlinePSTNGateway using the InboundTeamsNumberTranslationRules, InboundPSTNNumberTranslationRules, OutboundTeamsNumberTranslationRules and OutboundPSTNNumberTranslationRules parameters, and they apply in the order listed. in context
• Microsoft's example translates a four-digit called number arriving from the SBC into E.164 with an InboundTeamsNumberTranslationRules entry matching ^(\d{4})$, so a caller who dials only four digits still reaches the Teams user. in context
• Inbound Direct Routing calls reach a Teams user by reverse number lookup on the called number, and an inbound translation rule on the SBC can rewrite a called number that does not match the format assigned to users. in context
• To avoid double normalization, Microsoft recommends that Direct Routing customers normalize numbers to a leading + with dial plans and, if the SBC needs another format, remove the + with a route-based translation rule on the SBC. in context
• Number translation rules are applied per SBC in the order they are listed, are managed with the *-CsTeamsTranslationRule cmdlets and attached through four Inbound/Outbound Teams/PSTN parameters of New- or Set-CsOnlinePSTNGateway, and are capped at 400 rules in total. in context
• Microsoft recommends that Direct Routing customers use dial plans that normalise numbers to include a plus and then remove the plus with a route-based translation rule, to avoid double normalisation. in context
• Where the user's effective dial plan applies no normalisation rule to the dialled number, the Teams service dial plan prepends +CC using the country or region code of the dialling user's usage location, for Calling Plans, Direct Routing and PSTN conference dial-out. in context
• Translation rules are created with New-CsTeamsTranslationRule and attached to a gateway with New-CsOnlinePSTNGateway or Set-CsOnlinePSTNGateway through the InboundTeamsNumberTranslationRules, InboundPSTNNumberTranslationRules, OutboundTeamsNumberTranslationRules and OutboundPSTNNumberTranslationRules parameters. in context
• Inbound Direct Routing calls are matched to a Teams user or resource account by Reverse Number Lookup on the dialled number-string, so where the SBC passes through a format that does not match the assigned number-string an inbound translation rule on the gateway is needed. in context
• The maximum total number of translation rules is 400, the maximum parameter-name length is 100 symbols, the maximum pattern length is 1024 symbols and the maximum translation length is 256 symbols. in context
• Number translation rules are applied at the SBC level, multiple rules can be assigned to one SBC and they are applied in the order in which they appear when listed in PowerShell. in context
• Example 4 (outbound call to a four-digit number) in Microsoft's Direct Routing translation article labels the translations with InboundTeamsNumberTranslationRules and InboundPSTNNumberTranslationRules. That appears inconsistent with an outbound call, and Example 3 uses the Outbound parameters. The example should not be used as the reference for parameter semantics. inferred in context
• Teams assigns translation rules to an SBC through four online PSTN gateway parameters: InboundTeamsNumberTranslationRules, InboundPSTNNumberTranslationRules, OutboundTeamsNumberTranslationRules and OutboundPSTNNumberTranslationRules. in context
• When a Teams user's effective dial plan applies no normalization rule to a dialed number, the service dial plan prepends +CC, where CC is the country code of the user's usage location. in context
• Teams allows at most 400 translation rules in total. Rule names are limited to 100 symbols, patterns to 1024 symbols and translations to 256 symbols. in context
• Teams Direct Routing number translation rules are applied at the SBC (online PSTN gateway) level, in the order they are listed in PowerShell. The order can be changed. in context
• To avoid double normalization, Microsoft recommends that Direct Routing customers normalize to a '+' form in dial plans and then remove the '+' with a route-based translation rule if the SBC needs it. in context
• Example 4 in Microsoft's Direct Routing translation article appears internally inconsistent: it describes an outbound call but names Inbound* parameters, and its translated To header shows 4255555555 rather than the 4255550100 in the Request-URI. inferred in context
• If a user's effective Teams dial plan applies no normalization rule to a dialed number, the Teams service dial plan prepends '+CC', where CC is the country or region code of the user's usage location. in context
• Direct Routing allows at most 400 number translation rules in total, with pattern strings up to 1024 symbols and translation strings up to 256 symbols. in context
• Direct Routing translation rules are attached to an SBC through four gateway parameters: InboundTeamsNumberTranslationRules, InboundPSTNNumberTranslationRules, OutboundTeamsNumberTranslationRules and OutboundPSTNNumberTranslationRules, and they are applied in the order they are listed. in context
• For an outbound Direct Routing call, the dialed number is first normalized by the user's effective dial plan, then matched to a PSTN usage and voice route, and then sent to the route's SBC. Any outbound number translation rules on that SBC's online PSTN gateway object change the number format the SBC receives. in context
• If the user's effective dial plan applies no normalization rule to a dialed number, the Teams service dial plan prepends '+CC', using the country code of the user's usage location. This applies to Calling Plans, Direct Routing and PSTN conference dial-out. in context
• Microsoft documents a maximum of 400 translation rules in total. A rule name can be up to 100 symbols, a pattern up to 1024 symbols and a translation up to 256 symbols. in context
• Number translation rules are applied at the SBC level. When an SBC has several rules, they are applied in the order they appear when listed in PowerShell, and that order can be changed. in context
• Route-based translation rules are created with New-CsTeamsTranslationRule. They are attached to an SBC through four online PSTN gateway parameters: InboundTeamsNumberTranslationRules, InboundPSTNNumberTranslationRules, OutboundTeamsNumberTranslationRules and OutboundPSTNNumberTranslationRules. in context

Cite this source record

APA

WarmTransfer. (2026, September 10). Translate phone numbers for Direct Routing. WarmTransfer. https://warmtransfer.net/knowledge/sources/ms-learn-dr-translate-numbers

BibTeX

@misc{warmtransfer-ms-learn-dr-translate-numbers,
  title  = {Translate phone numbers for Direct Routing},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/sources/ms-learn-dr-translate-numbers},
  note   = {Microsoft, accessed 2026-09-21}
}