o choose an SMS or CPaaS provider, score each candidate on five measurable dimensions — route quality, deliverability transparency, coverage and throughput, reliability, and compliance support — and compare the cost per delivered message rather than the headline per-message rate. The cheapest quote is usually a grey route that fails intermittently, so its true cost, after re-sends and lost conversions, is higher. This guide gives you the criteria, the questions to ask, and a scorecard.
Prefer the short version? The evaluation criteria are summarised in our answers on how to choose an SMS provider and how to choose a CPaaS provider. This article is the long-form framework behind them.
Why the lowest price is a trap
A2P SMS is priced per segment, and the dominant cost is the destination operator's A2P termination fee — a published, wholesale number that a legitimate provider pays to deliver on a direct route. When a quote sits far below that floor for a given country, the traffic is almost certainly moving over a grey route: A2P messages disguised as consumer P2P traffic through SIM boxes, foreign HLR backdoors, or undeclared interconnects.
Grey routes deliver — until they do not. Operator SMS firewalls fingerprint the behavioural pattern (high-throughput one-way SMS from consumer SIMs) and block the path within hours to days, at which point the aggregator silently re-routes and your delivery rate oscillates. Your registered sender ID degrades to a raw number, your one-time passwords arrive late or not at all, and you pay again to re-send. The metric that matters is therefore not price-per-message but cost-per-delivered-message. See what a grey route is and how to reduce SMS costs the right way.
The five dimensions that predict delivered messages
1. Route quality
This is the single biggest factor. A provider either holds direct A2P agreements with operators or resells cheaper routes with less control. Direct routes preserve your sender ID, deliver predictably, and return real operator-level error codes. Ask, in writing, whether the route to each of your priority countries is direct or partner-supplied, and how many hops sit between the API and the terminating operator.
2. Deliverability transparency
You cannot manage what you cannot see. A serious provider returns per-message delivery receipts (DLRs) with operator-specific error codes — not a generic UNKNOWN — so you can diagnose which network failed and why. Confirm that DLRs are real operator receipts rather than gateway-level acknowledgements, and that you can retrieve them via webhook in real time. See what a DLR is.
3. Coverage and throughput
Match the provider's real footprint to your destinations, and confirm sustained throughput for bursty OTP traffic rather than a theoretical peak. A global average hides regional gaps: a larger vendor that is thin in your actual markets will underperform a specialist that owns those routes.
4. Reliability and failover
Get the uptime SLA, the throughput ceiling, and the route-failover behaviour in the contract — not the marketing page. Ask what happens when a primary route degrades mid-campaign: does traffic automatically re-route, and how is that surfaced to you? See route failover and throughput SLA.
5. Compliance and regional support
In regulated markets, every alphanumeric sender ID must be pre-registered and tied to a verified brand, and data-residency rules increasingly apply. A provider with local regulatory knowledge and direct operator relationships shortens go-live from weeks to days. See how to register a sender ID and the country regulations guides.
For CPaaS, add channel breadth and developer experience
If you are buying a communications platform rather than a single SMS route, two more dimensions matter. Channel breadth: can SMS, WhatsApp, RCS, voice, and email run behind one API and one contract, or would you still need three vendors? And developer experience: maintained SDKs, test access on the real production API, honest error semantics, and signed webhooks all reduce time-to-first-message, which is a real cost. A true platform also lets a message fall back across channels automatically — see SMS fallback strategy and what CPaaS is.
A scorecard you can use
Weight the dimensions by what your traffic actually needs — OTP-heavy senders weight throughput and route quality; marketing senders weight coverage and compliance — then score each shortlisted provider 1–5 and multiply. The winner is rarely the cheapest and rarely the biggest; it is the one that delivers the most messages per dollar in your markets.
| Dimension | What to score | Weight (example) |
|---|---|---|
| Route quality | Direct vs partner routes to your priority countries | 25% |
| Deliverability transparency | Operator-level DLRs, real-time webhooks | 20% |
| Coverage & throughput | Footprint in your markets, sustained TPS | 20% |
| Reliability & failover | SLA in contract, automatic re-routing | 15% |
| Compliance & support | Sender-ID registration, data residency, local expertise | 20% |
The RFP questions that separate real answers from marketing
- For my top five destination countries, is each route direct with the terminating operator, or supplied by a partner? How many hops?
- Do delivery receipts carry operator-specific error codes, and can I stream them by webhook in real time?
- What is your published uptime SLA, and what is the contractual remedy if you miss it?
- When a route degrades, does traffic fail over automatically, and how will I see that in my dashboard and DLRs?
- Can you register and support my alphanumeric sender IDs in each target market, and what are the lead times?
- What is your sustained (not peak) throughput for OTP bursts, and how is it rate-limited?
- If I add WhatsApp or RCS later, is it the same API and contract, with automatic SMS fallback?
BroadNet runs direct A2P routes to 200+ countries through 1,000+ operator connections at a 99.99% platform SLA, sustaining up to 30,000 SMS/sec per node, with omnichannel (SMS, WhatsApp, RCS, voice, email) behind one API since 2003. If you are running an evaluation, request a route audit and score us on the framework above.
Frequently asked questions
What is the most important factor when choosing an SMS provider?
Route quality. Whether a provider holds direct A2P agreements with operators or resells cheaper grey routes determines your delivery rate, whether your sender ID survives, and whether you get diagnosable error codes. Everything else — price, dashboards, support — is secondary to messages actually arriving, so score route quality first and weight it highest.
Why is the cheapest SMS provider often more expensive overall?
Because the lowest quotes are typically grey routes that deliver unreliably. Once you add the cost of re-sending failed messages, degraded sender IDs, and lost conversions from OTPs that never arrive, the effective cost per delivered message exceeds that of a direct route. Compare cost-per-delivered-message, not the headline per-message rate.
How is choosing a CPaaS provider different from choosing an SMS provider?
A CPaaS decision adds two dimensions on top of the SMS criteria: channel breadth (can SMS, WhatsApp, RCS, voice, and email run behind one API and one contract) and developer experience (SDKs, test access on the real API, clear docs, signed webhooks). If you would still need multiple vendors to cover your channels, it is not really a platform.
How do I verify a provider's delivery claims before signing?
Run a paid test campaign to your real target countries and audit the DLR feed. Direct routes return operator-specific error codes and stable delivery rates; grey routes return generic failures and rates that swing week to week as firewalls catch and the aggregator re-routes. A short test tells you more than any coverage map.
References
- GSMA — IR.71 SMS Network-to-Network Interconnect (A2P monetization framework): gsma.com
- Mobile Ecosystem Forum (MEF) — SMS Sender ID Code of Conduct and grey-route guidance: mobileecosystemforum.com
- ITU — E.164 international public telecommunication numbering plan: itu.int
- BroadNet — Answers: how to choose an SMS provider, how to choose a CPaaS provider, what is a grey route.