A Teams call that drops, cannot reach an external number or leaves customers stuck in a queue is not a Microsoft Teams problem alone. It is a business communications problem. The best Teams Direct Routing providers connect Teams to the public telephone network in a way that gives your people reliable calling, your customers a consistent experience and your business more control over cost and change.
For UK organisations moving away from an ageing PBX, Direct Routing can be a practical route to cloud calling without forcing every team into a one-size-fits-all package. The provider you choose matters just as much as the technology. You need more than SIP trunks and a session border controller in the background. You need clear ownership, responsive support and a plan that reflects how your people actually work.
What Teams Direct Routing changes for your business
Microsoft Teams is where many employees message, meet and collaborate. Direct Routing adds external calling by connecting Teams to a specialist voice network, rather than relying solely on Microsoft’s Calling Plans. This can let you keep existing business numbers, add geographic and non-geographic numbers, route calls intelligently and support a mix of office-based, mobile and remote workers.
It also gives you choices. A customer service team may need call queues, reporting and resilient routing, while a small group of office users may simply need to make and receive calls from their Teams app. Direct Routing can accommodate both, provided the design is sensible.
For many SMEs and mid-sized businesses, the commercial case is equally persuasive. Calling plans can suit straightforward requirements, but Direct Routing may offer more flexibility around call packages, number management, international calling and integration with existing telecoms services. It is not automatically the cheapest option. The value comes from matching the service to real call volumes, locations and operational needs rather than paying for features nobody uses.
What makes the best Teams Direct Routing providers?
There is no universal number-one provider. A UK business with 40 users, a single main number and a mobile workforce will assess the market differently from a multi-site organisation with contact centre teams and overseas offices. The right choice sits at the point where technical capability, commercial clarity and day-to-day service meet.
Start with the network. Ask how calls are routed, what resilience is built in, where numbers can be supplied and ported, and how the provider manages incidents. A low monthly price means little if it comes with slow fault ownership or unclear escalation when your main line is unavailable.
Then look at management. The strongest providers make it easy to add users, allocate numbers, adjust call handling and understand monthly spend. Some offer a self-service portal; others pair that with an experienced support team that will make changes for you. Neither model is inherently better. Busy IT teams may value control, while leaner teams often prefer a partner that takes responsibility for the detail.
Finally, assess the wider communications picture. If you need contact centre functionality, recording, compliance controls, meeting rooms, mobile integration or a phased migration from legacy telephony, a provider with broader expertise can reduce the number of suppliers you need to manage.
Providers worth considering for UK organisations
The following providers represent different approaches to Teams voice. They are not a fixed league table. Product availability, Microsoft programme status, commercial terms and support models can change, so treat this as a focused shortlist for conversations rather than a final procurement decision.
Gamma
Gamma is a familiar name in the UK business communications market, with a broad partner network and a strong presence in cloud voice and connectivity. It can be a sensible option for organisations that want Teams calling connected to wider telecoms services, particularly where they already work with a Gamma channel partner.
Its scale can be reassuring, but the experience often depends on the reseller or managed service partner delivering the solution. Ask who will handle onboarding, number porting, user changes and fault escalation. The answer should be specific, not a generic promise of support.
Pure IP
Pure IP is often considered by businesses with international requirements. Its focus on global voice connectivity and Microsoft Teams integration can make it a good fit for organisations managing sites, users or customer-facing numbers across several countries.
For a UK-only business with straightforward calling needs, that international reach may be more than you require. For a company expanding overseas or seeking consistency across regions, it can be a meaningful advantage. Check how local number availability and regulatory requirements are handled in each territory that matters to you.
Colt
Colt tends to be associated with larger organisations that need enterprise-grade connectivity alongside voice services. Businesses with multiple offices, significant network demands or complex security expectations may find its broader infrastructure portfolio attractive.
That does not rule Colt out for mid-market firms, but the fit needs to be right. If your priority is a fast, highly personal deployment for a modest user base, a specialist managed provider may feel more proportionate. If voice, network and international connectivity must be planned together, a larger carrier can bring useful depth.
CallTower
CallTower is a cloud communications provider with a strong Teams voice proposition and experience across collaboration platforms. It can appeal to organisations looking for a managed service layer around Microsoft Teams, especially where unified communications is part of a wider workplace technology strategy.
The key questions are practical ones: how UK numbers are managed, what local support looks like, and whether the service model aligns with your internal capabilities. Global providers can offer breadth, but a UK business should still expect clear accountability when an issue affects customers here.
A UK managed communications partner
For many SMEs, the best option is not a household-name carrier but a managed communications partner that designs and supports the full service around their business. This approach can combine Teams Direct Routing with hosted telephony, SIP, contact centre tools, mobile services and compliance support under one accountable relationship.
That is where a provider such as Bulb Tech can be particularly relevant. The focus is less on selling a standalone voice route and more on making calling work across the organisation, from a receptionist handling customer calls to a remote colleague using a mobile device. It is a model that suits businesses that want accessible expertise without building a specialist telecoms team in-house.
Questions to ask before you choose
A polished demo is useful, but it will not reveal every operational detail. Ask each shortlisted provider how it will manage the migration of your existing numbers, including timescales, testing and what happens if a port is delayed. Number porting is often the moment when a communications project becomes very real, so it deserves more attention than a line in a proposal.
You should also ask about resilience in plain language. If your main internet connection fails, can calls be redirected? If Microsoft Teams is unavailable to a user, what alternative calling options exist? If your office closes unexpectedly, can administrators change routing quickly? Good providers explain these scenarios without hiding behind acronyms.
Commercially, establish whether pricing includes session border controller services, call bundles, implementation, support, number rental and contract changes. Check for minimum user commitments, out-of-bundle call charges and any costs associated with moving away later. Predictable monthly spend is valuable, but only when you understand what sits behind it.
Security and compliance deserve equal attention. Depending on your sector, you may need call recording, retention controls, role-based access, audit trails or assistance meeting data protection obligations. The provider should be able to explain responsibilities clearly: what it manages, what Microsoft manages and what remains with your organisation.
Plan the move, not just the purchase
Teams Direct Routing works best when it is treated as a communications change rather than an IT switch-on. Map the calls that matter most: the main company number, reception, sales enquiries, service lines, out-of-hours routing and emergency calling. Speak to the people who answer those calls every day. They will spot issues a technical diagram misses.
A phased rollout is often the calmer route. Pilot the service with a representative group, test call flows and mobile use, then refine the configuration before moving the whole business. This also gives managers time to communicate the change and help colleagues build confidence in the new way of working.
The right provider will make Teams feel less like another system to manage and more like a dependable place to work and speak with customers. Choose the partner that asks thoughtful questions about your business, gives straight answers about trade-offs and stays present after the numbers have been ported. That is how communications change becomes a lasting improvement, rather than another project your team has to carry alone.
