Voice Service Models: Reseller, Referral, and Full Stack

The MSP's Guide to VoIP: Part 2 of 20

Disclaimer: This post is educational content about the business considerations of offering VoIP services as an MSP. It is not legal advice. Regulations change, interpretations vary, and your specific situation may differ from the general scenarios described here. Consult with a telecom attorney to determine how these regulations apply to your business.

In the previous post we laid out the honest case for and against adding voice to your MSP. If you have decided to move forward, or even if you are still evaluating, the next question is how. And "how" is not a single answer. It is a spectrum that ranges from barely touching the phone system to owning every piece of it.

Where you land on that spectrum determines your margin, your support obligations, your technical requirements, your hiring needs, and your regulatory exposure. Get this decision wrong and everything downstream gets harder. Get it right and you have a framework that scales with your business.

This post walks through each model in detail so you can make an informed choice. We will cover four distinct approaches: referral, white-label resale, co-managed, and full stack. Most MSPs start at one end of this spectrum and move along it over time. Understanding the full range upfront helps you pick a starting point that matches your current capabilities while leaving room to grow.

Referral: the lightest touch

The referral model is barely a voice business at all, which is exactly its appeal for MSPs who want to address client demand without taking on operational complexity.

Here is how it works. A client asks about phones. You introduce them to a hosted VoIP provider you trust. The provider handles the sales process, provisioning, support, and billing. You might earn a one-time referral bonus or an ongoing trailing commission, typically 5 to 15 percent of the client's monthly spend. Your involvement after the introduction ranges from minimal to zero.

Where the referral model makes sense

If your MSP is small, your support team is already at capacity, and voice is not a strategic priority, referral is the rational choice. You address the client's need, you keep a voice competitor out of the account (sort of), and you earn some passive income without adding support load.

It also makes sense as a temporary measure while you build voice competency. You can refer clients today while training your team, evaluating platforms, and preparing to move up the spectrum. Better to refer a client to a competent provider than to deliver a mediocre experience yourself.

Where it falls apart

The fundamental problem with referral is that you have given away the client relationship for a critical piece of infrastructure. The voice provider now has regular contact with your client. They are in the office during phone deployments. They are on the phone when something breaks. And they are a technology company with their own sales team, which means they are positioned to offer other services that overlap with yours.

You also have no control over the client experience. If the provider delivers poorly (bad call quality, slow support, botched number ports), the client may blame you because you made the introduction. Your reputation is tied to a company you do not control.

The commission revenue is real but thin. On a 50-seat client paying $25 per user, a 10 percent trailing commission is $125 per month. That is not nothing, but it is a fraction of what you would earn in a resale model, and it comes without any of the stickiness that makes voice strategically valuable.

Regulatory implications

In a pure referral model, your regulatory exposure is essentially zero. You are not providing telecommunications services. You are making an introduction. The provider holds the necessary licenses, files the required regulatory reports, and manages compliance with telecommunications law. This is one of the genuinely nice things about the referral model.

White-label resale: your brand, their platform

White-label resale is where most MSPs land when they get serious about voice. You sell a hosted VoIP platform under your own brand (or a co-branded arrangement) while the underlying infrastructure is operated by a wholesale provider.

The client sees your name on the portal, your logo on the invoices, and your number on the support line. Behind the scenes, the phones register to the wholesale provider's servers, the calls route through their SIP trunks, and the platform runs on their infrastructure. You are the face of the service. They are the engine.

How the economics work

Wholesale hosted VoIP pricing typically runs $8 to $18 per seat depending on the provider, feature set, and your volume. You sell at retail rates of $20 to $35 per seat. The spread is your gross margin on voice, and it is meaningfully better than referral commissions.

On that same 50-seat client at $28 retail and $12 wholesale, you are generating $800 per month in gross margin. Across ten clients of that size, that is $8,000 per month in recurring gross margin from voice alone. Subtract your support costs and you still have a real business.

Beyond the per-seat margin, many wholesale providers offer revenue share on usage-based services like international calling, toll-free numbers, call recording storage, and fax. These are smaller numbers individually but they add up, and they come with almost no incremental support cost.

The support model

Here is where the tradeoff lives. You own first-line support. When a client calls because their phones are not working, they are calling you. You need to triage the issue, determine whether it is something on the client's local network, something with their internet connection, or something on the platform side, and either resolve it yourself or escalate to the wholesale provider.

The amount of troubleshooting you can do yourself depends on what the wholesale provider gives you access to. Good wholesale providers give you an admin portal with visibility into registration status, call logs, quality metrics, and configuration. They give you the ability to make most day-to-day changes (adding extensions, modifying call routing, updating auto attendants) without opening a ticket. They have responsive partner support that treats your escalations seriously.

Bad wholesale providers give you a limited portal, restrict your ability to make changes, and have support queues that treat you like a retail customer. The difference between a good and bad wholesale provider will define your experience with the resale model, so platform selection matters enormously. We will cover that in detail later in this series.

The skills your team needs for white-label resale are a step up from referral but not as deep as full stack. They need to understand how VoIP works well enough to triage issues. They need to be able to distinguish between a network problem and a platform problem. They need to know how to read MOS scores and recognize when jitter or packet loss is the culprit versus a provisioning error. They need to be comfortable configuring phones, managing call flows, and handling the day-to-day changes that clients request.

What they do not need is deep PBX administration, SIP protocol expertise, or carrier relationship management. The wholesale provider handles those layers.

The client experience

When done well, white-label resale is invisible to the client. They see your brand, they call your team, and they get their issues resolved. They do not know or care that the platform runs on someone else's infrastructure, just like they do not know or care which data center hosts their Office 365 tenant.

The risk is when the seam between you and the wholesale provider becomes visible. If a client calls you with a one-way audio problem and you have to tell them "I've escalated it to our platform team and I'm waiting to hear back," you have exposed the layered structure and the client is now wondering who is actually running their phone system. Minimizing these moments requires strong triage skills on your team and a responsive wholesale provider.

Regulatory implications

This is where things get more nuanced, and it is worth understanding even at this stage. When you resell voice services under your own brand, you may be considered a telecommunications service provider in some jurisdictions. The regulatory landscape varies significantly by country and by state or province within countries.

In the United States, reselling VoIP services can trigger obligations to file with the FCC, contribute to the Universal Service Fund, comply with CPNI (Customer Proprietary Network Information) rules, and support E911 emergency calling. Some wholesale providers structure their agreements so that they remain the provider of record for regulatory purposes, which keeps these obligations on their side. Others structure it so that you, as the reseller, bear some or all of these obligations.

There is an important distinction here that catches many MSPs off guard. If you pay USF surcharges on your own business VoIP lines, that is a consumer obligation passed through by your provider. It does not mean you are compliant as a provider. The moment you begin offering interconnected VoIP to clients, you may cross the threshold into voice service provider territory, with separate obligations including FCC registration, obtaining an Operating Company Number (OCN), and filing Form 499-A. Even in a resale arrangement, depending on how the wholesale agreement is structured, you, not the wholesale provider, may be the entity with FCC filing obligations. Read the agreement carefully and understand which party is the provider of record before you sign.

You need to understand which structure your wholesale agreement uses before you sign it. "I didn't know I had regulatory obligations" is not a defense that regulators find compelling. We will cover the compliance landscape in detail in the final section of this series (posts 17 through 20), but the takeaway for now is: ask the question early and get a clear answer.

Co-managed: shared responsibility

The co-managed model sits between white-label resale and full stack. You deploy and manage the phone system on the client's behalf, but you do it in partnership with a provider who retains responsibility for certain layers of the stack.

This model takes different forms depending on the provider and the arrangement. In one common version, you deploy a provider's on-premises or cloud PBX platform at the client site, configure and manage it, and handle first-line support. The provider manages the trunking, maintains the platform software, and provides escalation support. You have deeper access to the system than in a resale model (you might have full admin access to the PBX rather than a limited portal), but the provider still owns the infrastructure components.

In another version, you deploy your own PBX infrastructure (say, an open-source PBX on a VM) but use the provider for SIP trunking and PSTN connectivity. You manage the PBX. They manage the trunk. This is a common stepping stone toward full stack because it lets you build PBX expertise while outsourcing the carrier relationships and regulatory compliance associated with trunking.

Economics of co-managed

The margins in co-managed arrangements are higher than resale because you are delivering more value and taking on more responsibility. Per-seat economics vary widely depending on the specific arrangement, but the general pattern is that you capture more of the revenue because you are doing more of the work.

The flip side is that the work is real. You are provisioning PBX systems, managing SIP trunk configurations, handling firmware updates, and troubleshooting at a deeper level than resale requires. Your team needs stronger telephony skills, and the per-client support time is higher.

When co-managed makes sense

Co-managed works well for MSPs that have some telephony expertise on staff and want to offer a more customized solution than a hosted platform allows. Some clients need PBX features or integrations that hosted platforms do not support well, and co-managed gives you the flexibility to deliver those without taking on the full complexity of owning the entire stack.

It is also a natural progression from resale. Once your team is comfortable with VoIP fundamentals and day-to-day voice support, taking on PBX management is a reasonable next step that increases your value to clients and your revenue per seat.

Regulatory implications

In a co-managed model, the regulatory picture depends heavily on the specific arrangement. If the provider retains the trunking relationship and acts as the provider of record, most regulatory obligations stay on their side. If you are contracting for trunks yourself, you start picking up obligations around E911, number portability, USF contributions, and potentially state-level telecommunications licensing.

The general rule is that the closer you get to owning the connection between the PBX and the public telephone network, the more regulatory surface area you take on. Trunking is where the regulatory weight lives.

Full stack: owning everything

In the full-stack model, you operate the PBX infrastructure, contract directly with SIP trunk providers for PSTN connectivity, manage phone numbers, and own the entire voice environment end to end. You are not reselling someone else's platform. You are the platform.

This is where the MSPs with deep telephony expertise live. It is also where the highest margins live, and where the highest operational complexity lives.

What full stack actually requires

Operating a full-stack voice provider means you are responsible for:

Platform infrastructure. Whether you run on-premises PBX hardware, virtual machines in a data center, or a cloud-hosted PBX, you are responsible for its uptime, performance, security, and maintenance. PBX software needs updates. Databases need backups. Certificates need renewal. Capacity needs planning. This is similar to managing any other server infrastructure, but with the added pressure that downtime means no dial tone for every client on that platform.

SIP trunk management. You contract directly with one or more Internet Telephony Service Providers for PSTN connectivity. You manage the trunk configuration, monitor trunk health, handle capacity planning, and deal with trunk-side issues like authentication failures or codec mismatches. You need to understand SIP registration, SIP signaling, and how to read a SIP trace when things go wrong.

Number management. You own the relationship with the number providers. Porting numbers in, porting numbers out, provisioning new DIDs, managing toll-free numbers, configuring caller ID. All of it runs through you. Number porting alone can be a significant operational burden, especially during the first few months of a client engagement when you are migrating their existing numbers.

E911 and emergency services. If you are providing the dial tone, you are responsible for ensuring that emergency calls work. This means E911 provisioning for every endpoint, keeping location data current as employees move or work remotely, and complying with applicable emergency services regulations. Getting this wrong has consequences that go beyond fines. It is a safety issue.

Client provisioning and management. Onboarding a new client means deploying and configuring their PBX environment, provisioning phones, setting up call flows, training users, and migrating their numbers. Ongoing management means handling moves, adds, and changes (MACs) as their organization evolves.

The margin math

Full-stack margins are compelling. When you own the PBX infrastructure and buy trunking at wholesale rates, your per-seat cost can be remarkably low. SIP trunk costs for a channel of PSTN connectivity might run $1 to $3 per month. PBX infrastructure costs, amortized across your client base, add another few dollars per seat. Your total cost per seat might be $5 to $10, compared to $12 to $18 in a resale model. At a $28 retail price, that is a significant improvement in gross margin.

But gross margin is not the whole picture. Your operating costs are higher because you need more skilled staff, more infrastructure, and more time per client for provisioning and support. The net margin depends entirely on your operational efficiency and your scale. At small scale, the fixed costs of running your own platform can eat into or exceed the margin advantage. At larger scale, the economics become very attractive.

The risk profile

Full stack carries risks that the other models do not. Platform outages affect every client simultaneously. A security vulnerability in your PBX software is your problem to patch. A misconfigured trunk can cause call quality issues or outright outages across your client base. And because you are the platform, there is no wholesale provider to escalate to. You are the last line.

This does not mean full stack is a bad choice. It means it is a choice that requires genuine preparation, adequate staffing, and robust operational processes. MSPs that run successful full-stack voice operations have typically been building their telephony expertise for years before taking on the platform responsibility.

Regulatory implications

Full stack has the most significant regulatory exposure of any model. When you are providing interconnected VoIP, meaning you are the entity that connects calls to the public telephone network, you are a telecommunications service provider in the eyes of regulators. "Interconnected VoIP" is the FCC's term for VoIP service that connects to the PSTN, and it is the trigger for provider classification.

In the United States, this means FCC registration, obtaining an Operating Company Number (OCN), USF contributions, state-level telecommunications licensing in every state where you have clients, CPNI compliance, E911 obligations, STIR/SHAKEN compliance, Robocall Mitigation Database filing, number portability compliance, and potentially local telecommunications taxes and surcharges. The regulatory overhead is not trivial. FCC enforcement actions against voice service providers for compliance failures have resulted in penalties exceeding six figures, and the FCC can assess USF contributions retroactively, meaning years of unfiled obligations can land as a single bill. For a small MSP, a single enforcement action can erase years of profit.

Some MSPs that operate full-stack voice providers structure their operations to minimize regulatory exposure, for example by using a licensed ITSP for trunking while managing the PBX themselves, which keeps the trunk-side regulatory obligations on the ITSP. This is essentially the co-managed model applied at scale, and it is a legitimate approach. But it limits some of the cost advantages of true full stack.

We will go deep on the regulatory landscape in posts 17 through 20. For now, the key point is that if you are considering full stack, regulatory compliance needs to be part of your planning from day one, not an afterthought.

Where most MSPs start versus where the money is

The pragmatic reality is that most MSPs start with white-label resale. It offers a reasonable margin, a manageable support load, and a well-defined boundary between what you are responsible for and what the wholesale provider handles. It lets you build voice competency and client volume without betting your business on a platform you are not ready to operate.

The money, in terms of per-seat margin, is in full stack. But the money only materializes if you have the scale, the expertise, and the operational maturity to run a platform efficiently. A small MSP running a full-stack voice operation with 200 seats is probably spending more on overhead than the margin advantage justifies. A larger MSP with 2,000 seats is in a very different position.

The most common progression looks like this: start with resale to learn the market and build competency, move to co-managed as your team's skills deepen and clients need more customization, and consider full stack when you have enough volume to justify the infrastructure investment and enough experience to operate it reliably.

There is no shame in staying at resale forever if it serves your business well. Not every MSP needs to become a telecom company. The point is to make a deliberate choice rather than drifting into a model by default.

How your choice affects the rest of this series

The service model you choose determines the relevance of different topics in this series. If you are doing white-label resale, the posts on network readiness, QoS, and troubleshooting are directly applicable to your daily work. The posts on platform operations and capacity planning are useful context but not your direct responsibility. The compliance posts are relevant but your wholesale provider shoulders most of the weight.

If you are heading toward co-managed or full stack, everything in this series is directly applicable. The network posts, the platform posts, the provisioning posts, the troubleshooting posts, and the compliance posts all describe things you will be doing yourself.

Regardless of your model, the next post matters for everyone. Client expectations around voice support are one of the most commonly underestimated aspects of adding voice to an MSP, and getting them right from the start saves an enormous amount of pain later.

Next up: Setting Client Expectations: What Voice Support Actually Looks Like, covering why voice support is different from data support, how to scope it in your MSA, and how to position yourself when the blame game starts.