Here at M12 Solutions, we use a number of different SIP trunking providers. For customers with more complex requirements, those with international presence, or who require diverse carrier options, we can provide different SIP trunking services to the same premises or different sites.
The largest UK SIP carrier, we've been working with Gamma since 2007.
Talktalk bought a smaller SIP provider called Tipical who specialised in offering inbound/outbound international SIP trunks/numbering.
Similar to TalkTalk, Colt have international SIP trunk number options, that leverage their global network.
Our most recent carrier option, and chosen for specific international SIP numbering options that Colt or TalkTalk don't have.