Route a UK toll-free number to MS Teams in 5 minutes

This tutorial routes a UK 0800 (or 0808) toll-free number from DIDHub into Microsoft Teams Direct Routing so an agent on Teams answers the call. We use the DIDHub managed SBC, so no on-prem SBC is required.

Step 1: Add the DIDHub managed SBC FQDN to your tenant

From a PowerShell session connected to Microsoft Teams (Connect-MicrosoftTeams):

# Register DIDHub managed SBC as a PSTN gateway
New-CsOnlinePSTNGateway -Fqdn "sbc-uk.didhub.io" -SipSignalingPort 5061 -Enabled $true -MediaBypass $false -ForwardCallHistory $true -ForwardPai $true

Step 2: Create a PSTN usage and voice route

Set-CsOnlinePstnUsage -Identity Global -Usage @{Add="DIDHub-UK-TollFree"}

New-CsOnlineVoiceRoute -Identity "DIDHub-UK-TollFree-Route" -NumberPattern "^\+448(00|08)\d+$" -OnlinePstnGatewayList "sbc-uk.didhub.io" -Priority 1 -OnlinePstnUsages "DIDHub-UK-TollFree"

Step 3: Apply a voice routing policy

New-CsOnlineVoiceRoutingPolicy "DIDHub-UK-Inbound" -OnlinePstnUsages "DIDHub-UK-TollFree"

# Assign to the user / group who will answer the toll-free
Grant-CsOnlineVoiceRoutingPolicy -Identity "agent@yourtenant.com" -PolicyName "DIDHub-UK-Inbound"

Step 4: Bind the toll-free number in DIDHub

In your DIDHub dashboard:

Step 5: Assign the number to a Teams user

Set-CsPhoneNumberAssignment -Identity "agent@yourtenant.com" -PhoneNumber "+448001234567" -PhoneNumberType DirectRouting

Step 6: Test the call

Dial 0800 1234 567 from any UK mobile or landline. The call should ring on the assigned agent's Teams app within 2-3 seconds.

Troubleshooting

• Call connects but no audio: Set -MediaBypass $false on the PSTN gateway. UK toll-free traffic must flow via the SBC.
• Caller hears "the number you dialed is not valid": Double-check that +44800XXXXXXX matches the route's NumberPattern regex.
• Outbound from Teams fails: Toll-free is inbound-only by definition — create a separate route for outbound (geographic DID) if needed.

What you just built

An end-to-end UK toll-free → Teams Direct Routing flow with STIR/SHAKEN attestation, free inbound to your agents, and no on-prem SBC. Total provisioning time: typically under 5 minutes once Teams is licensed.