STIR/SHAKEN Compliance in 2026: The Complete Guide for VoIP Providers

If you originate, transmit, or resell voice traffic in the United States, STIR/SHAKEN compliance is no longer a technical nice-to-have. It is the price of admission to the public telephone network. In two enforcement actions in August 2025, the FCC’s Enforcement Bureau struck nearly 1,400 voice service providers from the Robocall Mitigation Database and directed every downstream carrier to stop accepting their traffic. Those companies did not lose a lawsuit or fail an audit. Most of them simply had incomplete or inaccurate paperwork.

Key Takeaways

• Almost everyone is covered now. Voice service providers, gateway providers, non-gateway intermediate providers, VoIP resellers, non-facilities-based providers, and MVNOs all carry obligations under the FCC’s caller ID authentication rules.
• The RMD filing is where providers actually get caught. Signing calls correctly but letting your database certification go stale is the single fastest route to being disconnected.
• March 1 is the date that matters every year. The FCC now requires annual recertification of existing RMD filings, with the filing window opening on February 1.
• Attestation level is a commercial issue, not just a compliance one. A-level attestation protects answer rates; habitual B or C signing on your own customers’ traffic invites analytics engines to label your numbers.
• You need an OCN before you can get a certificate. An FCC 499 Filer ID alone is not enough to obtain the SPC token that unlocks a SHAKEN certificate.
• The rules are tightening, not relaxing. During 2026 the FCC opened proceedings on know-your-customer duties, know-your-upstream-provider duties, codified attestation standards, and a significantly expanded RMD regime.
• Budget four figures, not five. For most small and mid-sized providers, first-year direct compliance costs land in the low thousands of dollars, excluding engineering time.

What Is STIR/SHAKEN? A Plain-English Definition

STIR/SHAKEN is a framework of interconnected industry standards that lets a phone company cryptographically sign the caller ID of a call it sends, and lets every carrier further along the route verify that signature before the call rings on a consumer’s handset. It answers one narrow question with mathematical certainty: did the provider that put this call on the network actually have the right to use the number in the caller ID field?

The two acronyms describe two halves of the same job. STIR stands for Secure Telephone Identity Revisited, a set of IETF specifications that define how a call’s identity information is packaged into a signed token. SHAKEN stands for Signature-based Handling of Asserted information using toKENs, the ATIS and SIP Forum profile that explains how carriers deploy STIR inside real SIP networks, who issues the certificates, and how trust is governed.

In practice, the originating provider adds an Identity header to the SIP INVITE. That header carries a PASSporT, a compact signed object containing the calling number, the called number, a timestamp, an attestation level, and an origination identifier. Terminating providers fetch the signer’s public certificate, check the signature, and pass the verification result to their call analytics and to the display on the phone. If you are new to how these SIP messages travel between carriers in the first place, our guide to what SIP trunking is and how it works covers the underlying transport that STIR/SHAKEN rides on.

What STIR/SHAKEN Is Not

A great deal of frustration in the operator community comes from expecting the framework to do things it was never designed to do. Being precise about the boundaries saves you from over-promising to customers.

• It is not a call blocking system. STIR/SHAKEN produces a trust signal. Blocking and labelling decisions are made separately by terminating carriers and third-party analytics providers.
• It does not authenticate the caller’s name. CNAM and branded calling are separate systems. A signed call can still display a misleading display name.
• It does not verify the human being on the line. It verifies the provider’s authority over the telephone number, nothing more.
• It does not work on legacy TDM segments. The framework is only operational on IP. Calls that traverse non-IP hops routinely lose their Identity header, which is why so many legitimate calls arrive unsigned.
• It does not stop robocalls by itself. It removes the anonymity that made illegal spoofing cheap, which is a meaningful but partial victory.

Who Must Comply With STIR/SHAKEN in 2026?

The original 2020 FCC caller ID authentication order applied to “voice service providers.” Every subsequent FCC action has widened the net, and the practical answer in 2026 is that if U.S. voice traffic touches your network or your billing relationship, you have obligations. The only real question is which ones.

Provider Type	Must Sign Calls?	Must Verify?	RMD Filing Required?	Notes
Facilities-based voice service provider	Yes, on IP portions	Yes	Yes	The core obligation established in 2020
Small provider (100,000 or fewer lines)	Yes	Yes	Yes	Extension was shortened; no general exemption remains
Gateway provider (accepts foreign-originated traffic)	Yes, must authenticate unsigned foreign calls	Yes	Yes	Heightened mitigation and traceback duties
Non-gateway intermediate provider	Yes, when it receives unauthenticated calls directly from an originating provider	Yes	Yes	Closed the last major structural gap
VoIP reseller / non-facilities-based provider	Yes, where it controls the IP network segment	Practically, via upstream	Yes	Most commonly overlooked category
MVNO	Yes, where applicable	Yes	Yes	Confirmed in a February 2026 FCC enforcement advisory
Enterprise or contact centre buying seats from a carrier	No direct duty	No	No	But your attestation level depends on your carrier’s KYC on you

The Reseller Trap

The most dangerous assumption in the wholesale market is “my carrier handles STIR/SHAKEN, so I am covered.” Your carrier may well sign your traffic. That does not discharge your own duty to file in the Robocall Mitigation Database, to maintain a written robocall mitigation plan, to name a responsible contact, and to respond to traceback requests within the FCC’s expected timeframes. The FCC has been explicit that the RMD filing obligation extends to non-facilities-based providers including VoIP resellers. If you are evaluating whether to operate as a reseller or build your own switching platform, our breakdown of how to start a VoIP business walks through both regulatory paths and their cost structures.

What About Non-IP Networks?

Because the framework only functions over IP, the Commission requires providers still running legacy technology to do one of two things: upgrade the relevant network segments to IP, or actively work to develop and deploy a caller ID authentication solution that operates on non-IP networks. “We have TDM in the middle” is not a standing excuse. It is a documented work-in-progress obligation that must be described in your mitigation plan, and it is one of the strongest business cases for finally retiring legacy trunks in favour of a modern unified communications platform.

STIR/SHAKEN Compliance Timeline: Every Deadline That Still Matters

Date	What Happened or Happens	Who It Affects
March 2020	FCC mandates STIR/SHAKEN in the IP portions of voice networks	All voice service providers
June 30, 2021	Primary implementation deadline; broad deployment begins	Large voice service providers
June 30, 2022	Accelerated deadline for small providers after the FCC moved the date up	Providers with 100,000 or fewer lines
June 30, 2023	Gateway providers must authenticate unsigned foreign-originated traffic	Gateway providers
December 31, 2023	Non-gateway intermediate providers must authenticate unsigned calls received directly from originating providers	Intermediate providers
August 6 and August 25, 2025	Enforcement Bureau removes 185 and then 1,203 non-compliant providers from the RMD; downstream carriers ordered to stop accepting their traffic	Non-compliant filers of every size
January 2026	Rules improving RMD effectiveness published, including a $100 per-filing fee and an annual recertification requirement	All RMD filers
February 1, 2026	Annual recertification filing window opens	All existing RMD filers
March 1, annually	Deadline to recertify your existing RMD filing	All existing RMD filers
April to July 2026	FCC opens proceedings on know-your-customer rules, codified attestation standards, know-your-upstream-provider duties, and an expanded RMD regime	Every provider in the call path

The pattern is unmistakable. Between 2020 and 2023 the FCC built the technical mandate. From 2025 onward it has been enforcing the paperwork and closing the behavioural loopholes. Providers who treat compliance as a one-time engineering project rather than an annual operational discipline are the ones getting disconnected.

How STIR/SHAKEN Works: The Call Flow, Step by Step

Understanding the sequence makes the compliance requirements intuitive rather than arbitrary. Here is what happens between the moment a caller presses dial and the moment a checkmark appears on the recipient’s screen.

1. The call is placed. A SIP INVITE arrives at the originating provider’s session border controller carrying a From or P-Asserted-Identity header with the calling number.
2. The provider evaluates its own knowledge of the caller. Does this customer own the number? Did the provider assign it? Is the customer verified? The answer determines the attestation level.
3. An authentication service creates a PASSporT. The signed token includes the calling number, called number, timestamp, attestation level, an origination identifier, and a pointer to the public certificate.
4. The token is attached as an Identity header and the INVITE is routed onward across the interconnect.
5. Intermediate providers pass the header through unchanged. Stripping or dropping it is itself a compliance failure, and unsigned calls arriving from an originating provider must be authenticated by the intermediate provider.
6. The terminating provider’s verification service retrieves the certificate from the URL in the header, validates the certificate chain against the trusted list, and checks the signature and timestamp.
7. The verification result feeds call analytics. A verified A-level signature raises the trust score. A missing or failed signature, or a habitual C-level pattern, pushes traffic toward “Spam Likely” territory.
8. The handset renders the outcome. Depending on the carrier and device, the recipient may see a verification checkmark, nothing at all, or a spam warning. Understanding how these signals reach the endpoint is useful when you are choosing softphones for your call teams, since display behaviour varies widely across clients.

Attestation Levels A, B, and C Explained

Every signed call carries exactly one of three attestation values. Competing guides usually stop at defining them. What matters operationally is understanding which level you are entitled to apply, what it costs you commercially to get it wrong, and why the FCC proposed in 2026 to codify these levels into binding rules rather than leaving them as industry convention.

Level	Name	What the Signer Is Asserting	Typical Scenario	Effect on Delivery
A	Full attestation	The provider authenticated the customer and confirmed the customer is authorised to use the calling number	Provider assigned the DID to a known, verified subscriber	Highest trust score; best answer rates and label outcomes
B	Partial attestation	The provider authenticated the customer but cannot confirm the customer’s right to use that specific number	Bring-your-own-number, enterprise PBX asserting an unverified DID range	Neutral to mildly negative; analytics may discount the call
C	Gateway attestation	The provider is simply passing the call on and can vouch for neither the customer nor the number	Foreign-originated traffic entering via a gateway provider	Weakest signal; frequently correlated with spam labelling

Why Attestation Level Is a Revenue Question

Terminating carriers and analytics vendors do not merely look at a single call. They build reputation profiles around originating providers and number blocks over time. A wholesale provider that signs the majority of its outbound traffic at B because it never invested in proper number-authority verification will slowly watch its customers’ answer rates decay, then field support tickets it cannot diagnose. The fix is unglamorous: tighten your onboarding, verify number ownership through Letters of Authorisation, and record that verification so you can legitimately sign at A.

This is precisely the territory the FCC moved into during 2026, proposing to codify the three attestation levels in its rules and to raise the bar for when a provider may assert full attestation. In other words, sloppy attestation is on a path from commercial disadvantage to regulatory violation. Contact centres that depend on outbound connect rates should treat this as a procurement criterion when choosing a VoIP provider, and should ask any prospective carrier for its attestation distribution in writing.

The Robocall Mitigation Database: Where Compliance Is Actually Won or Lost

If you remember one thing from this guide, make it this: the FCC does not disconnect providers for weak cryptography. It disconnects them for defective database filings. The RMD is a public FCC portal, and your entry is the document a downstream carrier checks before it agrees to accept your traffic.

What a Complete RMD Filing Contains

• A caller ID authentication certification stating whether you have complete, partial, or no STIR/SHAKEN implementation, and the basis for any extension or exemption you claim.
• A robocall mitigation plan describing the specific reasonable steps you take to avoid originating or transmitting illegal robocall traffic. Generic boilerplate is a recognised deficiency.
• Identifying information about the business, including legal name, all names under which you do business, physical address, and your role or roles in the call path.
• A named robocall mitigation contact with a working direct email and phone number who can respond to traceback requests.
• Disclosure of prior or pending robocall-related enforcement actions against the company or its principals.
• Your FCC 499 Filer ID and, where applicable, your OCN.

The Annual March 1 Recertification

The most consequential change in recent years is that RMD filings are no longer set-and-forget. Providers must recertify their existing filings annually, with the deadline set at March 1 and the filing window opening February 1. The FCC also adopted a $100 per-filing application fee as part of the same package, and separately proposed a sweeping expansion of RMD obligations in mid-2026 that would require mitigation plans containing affirmative, effective measures rather than descriptive narratives.

Practically, this means somebody in your organisation must own a recurring February task with a hard stop. Treat it like a licence renewal, not a marketing chore. Put it in the same operational calendar you use for your other annual telecom filings, and confirm every field is current, because an out-of-date contact number is enough to make a filing deficient.

What Happens If You Are Removed

Removal is not a fine you can appeal at leisure while continuing to trade. When the Enforcement Bureau strikes a provider from the database, it simultaneously directs all voice service providers and intermediate providers to cease accepting that provider’s traffic from a stated date. The commercial consequence is immediate and total.

• Your outbound calls stop completing across U.S. networks.
• Upstream and downstream partners terminate interconnection to protect their own compliance posture.
• Customers churn within days, because voice outages are not survivable for contact centres or clinics.
• You must refile, cure every deficiency, and wait for the Bureau to act before service can resume.
• Your removal is a matter of public record that future partners and enterprise buyers will find during due diligence.

A hundred-dollar filing fee and an afternoon of paperwork protect the entire enterprise value of a voice business. No other compliance task in telecom has that risk-to-effort ratio.

How to Become STIR/SHAKEN Compliant: An 8-Step Implementation Guide

This is the sequence most small and mid-sized providers follow. The dependencies are strict: you cannot skip ahead, because each step is a prerequisite for the next.

1. Classify yourself honestly. Write down every role you play: originating, terminating, intermediate, gateway, reseller, MVNO. Providers get into trouble by declaring one role while operating three.
2. Obtain an FCC 499 Filer ID. File Form 499-A with USAC. This is the foundational identity for a U.S. telecom carrier and a prerequisite for everything downstream.
3. Apply for an Operating Company Number. OCNs are issued through NECA. This is the gate most resellers hit, because a certificate authority cannot issue you a SHAKEN certificate without one.
4. Register with the Secure Telephone Identity Policy Administrator. The STI-PA validates your eligibility and issues a Service Provider Code (SPC) token.
5. Obtain a certificate from an authorised STI Certificate Authority. Present your SPC token, complete enrollment, and receive the private key and public certificate you will use to sign calls.
6. Deploy authentication and verification services. Integrate signing into your outbound path at the session border controller or softswitch, and verification on the inbound path. Providers running a Class 4 wholesale core and a Class 5 feature server need to decide which layer signs; our overview of practical VoIP setup steps and best practices is a useful companion when planning that integration.
7. Write and implement a real robocall mitigation program. Document customer vetting, traffic pattern monitoring, thresholds that trigger investigation, suspension procedures, and traceback response workflow with named owners and timeframes.
8. File in the Robocall Mitigation Database, then diarise the annual recertification. Verify every field, upload the plan, and set a recurring February reminder so the March 1 deadline never arrives as a surprise.

STIR/SHAKEN Compliance Costs: What to Actually Budget

Published pricing in this market is patchy, and operator forums are full of wildly different numbers because people are comparing different scopes. The table below reflects the ranges providers commonly report. Treat them as planning estimates and confirm current figures with each body directly, because fees change.

Cost Item	Typical Range	Frequency	Notes
FCC Form 499-A filing	No filing fee	Annual filing	Triggers USF and regulatory contribution obligations
Operating Company Number (NECA)	Roughly $375 to $550	One-time	Widely reported as the main gate for resellers
STI-PA registration and SPC token	Annual service provider fee	Annual	Scales with provider size in some fee schedules
SHAKEN certificate from an STI-CA	Roughly $450 to $500 per year	Annual	Per operating entity or OCN
Authentication / verification software or SaaS	Free open-source through several hundred dollars per month	Monthly	Depends on call volume and whether signing is bundled by your carrier
RMD application and recertification fee	$100 per filing as adopted	Annual	Effective date was still pending in early 2026; verify before relying on it
Regulatory counsel for filings	$500 to $5,000+	As needed	Often the best money spent for first-time filers
Engineering time	20 to 80 hours	One-time, plus maintenance	The largest hidden cost for in-house deployments

For a lean provider, direct first-year cash cost commonly sits in the low thousands. That figure should be modelled into your unit economics from day one rather than discovered in month three, which is one of several reasons regulatory budgeting features so heavily in serious VoIP business planning.

Build In-House or Buy Signing From Your Carrier?

Most providers face a genuine fork here, and there is no universally right answer. The decision hinges on whether you control number assignment and whether attestation quality is core to your value proposition.

Signing In-House With Your Own Certificate

• Pro: You control attestation logic and can legitimately sign at A for numbers you assign.
• Pro: Your identity travels with your traffic, which builds your own reputation with analytics engines.
• Pro: No dependency on an upstream partner’s compliance posture or outages.
• Pro: Stronger position in enterprise and government procurement, where buyers ask who signs.
• Con: Requires an OCN, annual certificate costs, and real engineering ownership.
• Con: You own key management, certificate rotation, and the consequences of misconfiguration.

Relying on Your Upstream Carrier to Sign

• Pro: Fastest route to market with no certificate procurement.
• Pro: Lower fixed cost, which suits low-volume or early-stage operators.
• Pro: The carrier absorbs the technical maintenance burden.
• Con: Your traffic often signs at B rather than A, with real answer-rate consequences.
• Con: You still must file and recertify in the RMD yourself. Nothing about this option removes that duty.
• Con: If your upstream is removed from the database, your service stops even though you did nothing wrong.

That last risk deserves emphasis. Counterparty compliance is now part of your own risk register. Before signing an interconnection agreement, look the partner up in the public RMD portal and confirm the filing is current. The same diligence applies when you shortlist wholesale suppliers from lists of leading VoIP companies or when you assess MVNO providers in the USA, since the FCC’s 2026 enforcement advisory confirmed MVNOs sit squarely inside these obligations.

What Is Coming Next: KYC, KYUP, and Codified Attestation

Almost every competing guide describes the rules as they were settled in 2023. That is the largest gap in the available literature, because the 2026 proceedings will reshape day-to-day operations far more than the original signing mandate did. Three threads are worth tracking closely.

• Know Your Customer (KYC). The Commission has sought comment on requiring originating providers to verify customer identity to a defined standard, retain the supporting documentation for a multi-year period, and produce it on request. If adopted, informal onboarding becomes a violation rather than a business choice.
• Know Your Upstream Provider (KYUP). A parallel proposal would place affirmative duties on providers accepting traffic from other providers, and would raise the bar for asserting full attestation. Wholesale carriers would need documented diligence on every upstream partner.
• An expanded RMD regime. The mid-2026 further notice proposed that mitigation plans contain affirmative, effective measures rather than descriptive text, alongside broader certification and compliance obligations for voice service providers.

There is a strategic reading here. Regulatory pressure is steadily pushing the industry toward provider-verified, well-documented traffic, and away from anonymous wholesale minutes. Providers who have already invested in genuine customer verification, traffic analytics, and clean attestation are about to find their compliance work converting into a competitive moat.

The AI Calling Wrinkle

Automated outbound voice has grown far faster than the regulatory vocabulary describing it. A compliant, consented, well-signed AI voice agent placing appointment reminders looks very different from an illegal robocall operation, but both are automated outbound calls at volume, and analytics engines are blunt instruments. If you deploy conversational AI on outbound paths, your protection is documentation and attestation quality: verified consent records, A-level signing, sensible pacing, and clean number reputation. Teams evaluating this technology should read our guides to AI-powered VoIP for enterprises and to selecting among leading AI voicebot companies in the USA with compliance capability as an explicit scoring criterion, and should ask any custom AI voicebot development partner how their platform handles consent logging and caller ID authority.

Seven Common STIR/SHAKEN Compliance Mistakes

1. Assuming the carrier’s compliance covers you. It covers signing. It does not cover your RMD filing, your mitigation plan, or your traceback duties.
2. Filing once and forgetting. The annual March 1 recertification is now the most common cause of accidental non-compliance.
3. Submitting a boilerplate mitigation plan. Plans that describe no specific, verifiable steps are treated as deficient.
4. Listing a stale contact. A bounced email or dead phone number for your robocall contact undermines the entire filing.
5. Signing everything at B out of convenience. It is technically permissible in some cases and commercially corrosive in almost all of them.
6. Stripping Identity headers at the SBC. Misconfigured header manipulation quietly destroys downstream verification and your reputation with it.
7. Ignoring counterparty risk. Interconnecting with a partner whose filing is defective exposes your service to sudden disconnection.

Most of these are governance failures rather than technical ones, which is encouraging: they are cheap to fix. Building a simple quarterly compliance review into the same operational rhythm you use to run your VoIP system effectively catches nearly all of them.

Frequently Asked Questions

What is STIR/SHAKEN compliance?

STIR/SHAKEN compliance means a U.S. voice provider digitally signs the caller ID on calls it originates over IP, verifies incoming signatures, runs a documented robocall mitigation program, and keeps a current certification on file in the FCC’s Robocall Mitigation Database. All four parts are required, not just the signing.

Who is required to comply with STIR/SHAKEN?

Voice service providers, gateway providers, non-gateway intermediate providers that receive unauthenticated calls, VoIP resellers, non-facilities-based providers, and MVNOs all carry obligations. Enterprises that simply buy phone seats from a carrier have no direct duty, although their attestation level depends on their carrier’s verification of them.

Do VoIP resellers need STIR/SHAKEN?

Yes. Even if an upstream carrier signs the traffic, a reseller must still file its own certification and robocall mitigation plan in the Robocall Mitigation Database, name a responsive robocall contact, and answer traceback requests. The FCC has confirmed the filing duty extends to non-facilities-based providers, including VoIP resellers.

What is the Robocall Mitigation Database?

The Robocall Mitigation Database is a public FCC portal where every voice service provider and intermediate provider files its caller ID authentication certification, its robocall mitigation plan, and its identifying and contact details. Downstream carriers check it before accepting traffic, so a defective filing effectively removes a provider from the network.

When is the annual STIR/SHAKEN recertification deadline?

Providers must recertify their existing Robocall Mitigation Database filings by March 1 each year, with the filing window opening on February 1. The FCC also adopted a $100 per-filing application fee as part of the same rules, so verify the current fee status before you file.

How much does STIR/SHAKEN compliance cost?

Most small providers spend a few thousand dollars in the first year. Typical items include an Operating Company Number from NECA at roughly $375 to $550 one-time, a SHAKEN certificate at roughly $450 to $500 per year, STI-PA fees, signing software, and a $100 database filing fee. Engineering time is the largest hidden cost.

What are STIR/SHAKEN attestation levels A, B, and C?

A, or full attestation, means the provider verified the customer and the customer’s right to use the calling number. B, or partial attestation, means the customer is known but number authority is unconfirmed. C, or gateway attestation, means the provider can vouch for neither. Higher attestation generally means better answer rates.

How do I get a STIR/SHAKEN certificate?

Obtain an FCC 499 Filer ID by filing Form 499-A, apply for an Operating Company Number through NECA, register with the Secure Telephone Identity Policy Administrator to receive an SPC token, then present that token to an authorised STI Certificate Authority to be issued your signing certificate.

What happens if a provider is not STIR/SHAKEN compliant?

The FCC’s Enforcement Bureau can remove the provider from the Robocall Mitigation Database and order all other carriers to stop accepting its traffic. In August 2025 nearly 1,400 providers were removed in two actions, which cut off their calls across U.S. networks until deficiencies were cured.

Does STIR/SHAKEN stop robocalls?

Not on its own. STIR/SHAKEN authenticates caller ID and produces a trust signal; blocking and spam labelling decisions are made separately by terminating carriers and analytics vendors. It makes illegal number spoofing far harder and traceback far faster, but it does not verify the caller’s name or intent.

The Bottom Line

STIR/SHAKEN began as an engineering mandate and has matured into an operating licence. The cryptography is, frankly, the easy part; certificates are inexpensive and the integration is well-trodden. What ends businesses is administrative drift: an unrenewed filing, a boilerplate mitigation plan, a contact who left the company two years ago, or an upstream partner nobody checked.

Treat compliance as a recurring operational discipline with a named owner and a calendar, and it costs you a few thousand dollars and a handful of hours each year. Treat it as a project you finished in 2022, and it costs you the company. The providers thriving in this environment are the ones who realised that verified identity, clean attestation, and defensible documentation are not overhead. They are the product. That is equally true whether you are a wholesale carrier, a reseller, or a provider serving small business VoIP customers who simply want their calls to be answered.

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Internal Linking Report

Existing published pages linked: Best Unified Communication Solution Provider, Best VoIP Softphones for Calls in 2026, Choosing a VoIP Provider, 7 Steps for VoIP Setup Tips and Practices, Top VoIP Companies, Top 10 MVNO Providers in the USA, AI-Powered VoIP 2026 Enterprise Guide, Leading AI Voicebot Companies in the USA for 2026, Best AI Voicebot Custom Development Companies USA 2026, Use a VoIP System More Effectively in 2026, VoIP for Small Business, and the Contact page.

Newly created draft posts linked: What Is SIP Trunking (draft), How to Start a VoIP Business (draft, linked twice in context).

Suggested future internal links: Class 4 vs Class 5 Softswitch Explained, SIP Trunk Pricing and Cost per Channel, White Label VoIP Reseller Platform Guide, Hosted PBX vs On-Premise PBX, VoIP Bandwidth Requirements per Call, and UCaaS vs CCaaS vs CPaaS.