For US ports, Microsoft publishes two separate LOA forms, one for geographic user, voice app and conferencing numbers and one for toll-free numbers. Microsoft highly recommends also supplying the CSR from the losing carrier and a recent invoice.

Checked 2026-09-25

Vendor
Microsoft
Product
Microsoft Teams Phone - Calling Plans
Subsystem
Letter of Authorization
Deployment
multi-tenant
Region
us
Release range
current as of 2026-09-25
Checked
2026-09-25

Sources

Cite this note

APA

WarmTransfer. (2026, September 25). Porting numbers to Microsoft Teams: source note teams-number-porting-us-loa-forms. WarmTransfer. https://warmtransfer.net/knowledge/claims/teams-number-porting-us-loa-forms

BibTeX

@misc{warmtransfer-claim-teams-number-porting-us-loa-forms,
  title  = {Porting numbers to Microsoft Teams: source note teams-number-porting-us-loa-forms},
  author = {{WarmTransfer}},
  year   = {2026},
  url    = {https://warmtransfer.net/knowledge/claims/teams-number-porting-us-loa-forms},
  note   = {Source note teams-number-porting-us-loa-forms, checked 2026-09-25}
}

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