Your starter stack got you to scale. Now margin loss, support delays, and compliance friction are slowing you down. Designed for product and engineering leaders, this playbook outlines a phased migration path to Bandwidth’s carrier-owned network to protect your developer roadmap while fixing your call/message economics.
The growth cap that limits you
The CPaaS that got you up and running with a credit card at 50K minutes of calls or 500k messages per month is not the same provider you need at 500K minutes or 1M messages. This happens when a stack built out of ease of onboarding starts cracking under the pressure of scale.
Most teams have switching inertia because of very real, competing roadmap priorities. Timing never feels perfect, and there is never reserved development team capacity for a migration in the quarter. It takes them time to realize that they’re in a crunch because they need an enterprise-scale CPaaS switch that’s already overdue, but they cannot afford to derail their current release cycle.
The engineering lift may seem bigger than the savings, but that inertia costs you as you get bigger.
Myth vs. reality of switching CPaaS providers
Myth
Reality
Switching means a quarter-long (or longer) rebuild
You can get started right away with a migration toolkit
There’s no dev capacity for a migration
A migration toolkit lets you refine your stack at your own pace
60-second billing for voice is just how voice pricing works
On a 1:06 call, you’re paying for 54 seconds of dead air, every call, forever
Latency problems are a model problem
Bad network makes good AI sound broken; the model gets blamed for what the network caused
Switching always requires re-registering messaging campaigns from scratch
While re-registering messaging campaigns is sometimes unavoidable, it’s possible to migrate messaging traffic with their original campaigns intact.
Deliverability rates are the same regardless of who you use
Carrier-direct relationships and AI-assisted registration tools change what actually reaches the handset. Not all CPaaS providers have the same path to the carrier.
When your outbound voice gets billed in full 60-second increments, a call that runs 1 minute and 6 seconds gets rounded up and billed as 2 full minutes. Bandwidth bills in 6-second increments, so that same 1:06 call is billed at 66 seconds, not 120. That gap, at a mid-market call volume, stops being a rounding footnote and starts being a line item.
Latency and support costs strengthen the case for a switch. Voice AI builders don’t just lose customers because a model gave a bad answer. Unnecessary hops in their calls add a beat of dead air before the answer arrives, affecting the Speech-to-Text conversion, and the caller assumes the AI is broken. The intelligence layer inherits whatever the infrastructure gets wrong.
Bandwidth’s direct-to-PSTN connectivity is purpose-built to reduce unnecessary hops.
93% of inbound traffic reaches Bandwidth’s network with one or fewer intermediate carrier hops.*
* Based on Bandwidth network data, North America
Bandwidth Support
Similarly with support. Bandwidth’s Signature Support gives you direct access to the technical guidance and expertise you need via phone, email, or support ticket at no additional cost.
Businesses that use messaging as a high-throughput, critical channel of communication turn to Bandwidth for enterprise-scale use and support across RCS as well as different SMS formats: Toll-free, 10DLC, short codes, global 2-way SMS, and alphanumeric SMS. Being a carrier, Bandwidth leverages direct carrier access and upfront AI-assisted registration tools to help reduce typical approval timelines, often to 2 to 3 business days.
The Developer Migration Toolkit: Bridging the integration gap
The fear here was never really about switching CPaaS platforms but about tweaking an application that’s actively in use. When you separate those two things, the rest of the transition gets easier.
Bandwidth simplifies the switch for Twilio Voice API users with our Developer Migration Toolkit: an open-source compatibility layer that translates Twilio’s TwiML into Bandwidth’s BXML in real time. This way, your existing Twilio-pattern API calls can point at Bandwidth without a rewrite, right up until you’re ready to build natively in BXML. Application logic stays exactly as it is, only the endpoints change.
What’s inside the Developer Migration Toolkit?
Compatibility Check:
A self-serve playground that lets you paste your TwiML and see translated BXML, and a score for estimated migration complexity.
Real-Time Translator:
Converts TwiML to BXML in real time using a fixed rulebook, not AI. It’s deterministic and straightforward about anything it can’t handle.
BXML Generator: Turns raw TwiML from the Translator into usable BXML for your migration to Bandwidth.
Agent-native:
Point Claude at the generated code and the Bandwidth CLI. With [band] handling number provisioning, app setup, and callback wiring, your agent completes the full integration, no dashboard required.
For a vertical SaaS team, that means no rip-and-replace sprint on an already-crowded roadmap. Run a compatibility check and test calls through Bandwidth right away. For a voice AI builder, it means no dev cycles pulled off ongoing product work to deal with under-the-hood infrastructure instead.
Check your Voice switch-readiness
Score your own migration complexity before you talk to anyone. Answer all six questions, add up the points, and check your total against the readiness key at the bottom.
What’s your current monthly voice call volume?
Your score
A. Under 10,000 minutes a month
1 pt
B. 10,000–100,000 minutes a month
2 pts
C. 100,000–1,000,000 minutes a month
3 pts
D. Over 1,000,000 minutes a month
4 pts
How would you describe your current TwiML setup?
Your score
A. A handful of simple flows: answer, forward, play a message
1 pt
B. Moderate logic: IVR menus, basic call routing
2 pts
C. 100,000–1,000,000 minutes a month
3 pts
D. Deeply custom: Flex, Segment, or multiple interconnected apps
4 pts
How sensitive is your use case to latency?
Your score
A. Not sensitive: asynchronous or notification-only calls
1 pt
B. Somewhat sensitive: standard customer support calls
2 pts
C. Sensitive: real-time conversational AI or voice agents
3 pts
D. Mission-critical: every beat of delay affects the product
4pts
How much engineering time can you realistically dedicate to a migration?
Your score
A. A dedicated team for a full sprint or more
1 pt
B. One or two engineers, part-time
2 pts
C. One engineer, squeezed in around other priorities
3 pts
D. None dedicated: this would happen in the cracks
4 pts
Which of these apply to your calls today?
Your score
A. None of the below
1 pt
B. Standard TCPA / A2P compliance only
2 pts
C. HIPAA, PCI, or another industry-specific regulation
3 pts
D. 911 / emergency calling obligations, or several overlapping regulations
4 pts
What’s your tolerance for support response time during the switch?
Your score
A. High: we can self-serve and troubleshoot
1 pt
B. Moderate: email support with reasonable SLAs is fine
2 pts
C. Low: we need fast, reliable support during the transition
3 pts
D. Zero: any downtime is a business emergency
4 pts
Calculate your score (_/24)
Total score
Readiness tier
What it means
6–10
Low complexity
It’ll be closer to a sprint than a project. You could realistically scope and pilot a migration within 30 days.
11–17
2 pts
A phased, 90-day migration is the right pace. Start with piloting one workflow on the Developer Migration Toolkit before moving the rest.
18–24
High complexity
Enough of your stack is involved that a migration engineer should be in the room from day one. That doesn’t mean it isn’t worth doing. It means the plan needs more structure before the first call moves.
Voice: 30, 60, 90-day plan
The switch is a sequence you can control, not a rip-and-replace project.
Day 0
Start here: Set up a Bandwidth account. If you’re already on the Bandwidth App, you’re good to go. If not, Bandwidth Build is your free developer account. Setup takes minutes; no contract required. You can use your Bandwidth Build account to evaluate Bandwidth’s Voice API on its own, or go ahead and provision a number to test call flows without signing a contract. Start for free →
Days 1–30
Compatibility Check: When you’re ready to evaluate a migration to Bandwidth, the Developer Migration Toolkit allows you to test how your current Twilio application would run on Bandwidth. Copy/paste your existing TwiML code into the Compatibility Check, and identify any minor code issues or blockers that could arise in your migration. Then, assess what’s translating cleanly and what may take a bit more work. See Migration Toolkit →
Days 31–60
Test your Twilio app with Bandwidth: Pick the call flow that you assessed in your Compatibility Check, and use the toolkit’s Real-Time Translator to make your call with Bandwidth. Test your call flows live against Bandwidth, and if you hit a feature we don’t support, the call surfaces that loudly. When you’re satisfied, the TwiML to BXML translation you’ve generated as part of your test is captured for the next step in your journey: creating useable BXML code for your migration. See dev docs →
Days 61–90
Migrate and scale: Once you’ve tested call flows with the Translator, use the BXML generator to produce a full coverage report, designed for your engineering and ops teams to evaluate the full effort required for migrating your application. The BXML generated at this step works as usable code for your new application, and because the Migration Toolkit is agent-native, simply point Claude in its direction to finish the integration with Bandwidth.
If you’ve used Bandwidth Build to get started and you’re ready to scale, you can upgrade to the full Bandwidth App experience when your contract is signed with the same account ID, with no re-integration required. Your voice setup doesn’t change, but your capabilities expand. When it comes to account provisioning (buying numbers, creating voice applications, activation), Bandwidth’s CLI makes it easy to cutover once the dev work is complete. Establish your new support relationship and monitoring baseline before you consider the migration done.
Bandwidth vs. Twilio and other competitors
Twilio
Telnyx
Sinch
Network
Owned Tier 1 network with 99.999% core network uptime globally, CLEC in the US, direct carrier relationships
Software layer over third-party carriers
Privately-owned IP network
Owns Inteliquent, fragmented across acquired platforms
Billing
6-second increments
60-second increments¹
60-second increments²
Varies based on product, service agreement, and destination³
Support
Direct access to network engineers
Tiered, chat and ticket-first at scale
Improving, still building an enterprise track record
Chat and email only, no unified support org
By owning the underlying network instead of renting it, Bandwidth fundamentally changes the economics and reliability of your communications stack.
Protect your margins: We cut out middleman markups to deliver true, software-scalable pricing directly to your bottom line.
Skip support loops: If deliverability drops, you skip the endless, multi-day ticketing loops. You get direct access to the engineers who own the routes and can fix issues on the spot.
Global, developer-first infrastructure: With clean Voice and Messaging APIs packed with direct-from-carrier analytics across a unified footprint of 65+ countries.
HIPAA support: Bandwidth offers a Business Associate Addendum (BAA) for messaging and voice channels to extend HIPAA obligations to Bandwidth as a service provider and support your Protected Health Information (PHI) safeguards under the HIPAA Security Rule.
What to do next
Talk to a migration engineer and get a personalized cost-of-staying calculation, built on your actual call volume, instead of an industry average.
Or start smaller: Build for free on Bandwidth Voice API and test it out for your use case.
The Developer Migration Toolkit handles voice. Messaging migration runs on a different track, and is more straightforward.
What stays the same
Most of the core logic in your Twilio messaging implementation carries over. Bandwidth’s Messaging API is a builder-first REST API that uses JSON, the same format most developers already prefer. If your Twilio setup uses a REST API (not TwiML) for messaging, you’re already building in the right direction.
What changes
The key differences are in callbacks and event handling. You’ll need to update endpoints to accept Bandwidth’s delivery receipts and message events: incoming message, message delivered, and message error. Database tables tracking delivery status will also need to reflect Bandwidth’s event schema.
Campaigns and number registration
This is where teams are apprehensive. If your 10DLC campaigns or short code registrations are in good standing with Twilio, it’s possible to migrate that traffic with campaigns intact rather than starting re-registration from scratch. Bandwidth’s carrier-direct relationships and upfront AI vetting tools help accelerate the process when re-registration is unavoidable, often bringing approval timelines down to 2 to 3 business days.
If you register your 10DLC campaigns directly with TCR as Campaign Service Providers (CSPs), you can now migrate approved, active campaigns to Bandwidth as your Connectivity Partner (CNP) without re‑registering or re-vetting. The transition is quick and cost-effective.
Messaging formats Bandwidth supports
Bandwidth covers the full enterprise messaging stack: 10DLC, short codes, toll-free messaging (with handset-level delivery receipts), RCS, global 2-way SMS, and alphanumeric SMS. If your current use case is 10DLC only, there’s also headroom to expand.
Deliverability is actually a carrier-relationship question. Carrier experience helps you navigate messaging requirements better and provides deeper insights into what’s really happening to your messages.
Every message travels across an elaborate web of interconnected carrier networks, hitting checkpoints along the way, and the rules at each checkpoint can change at any time. A provider with strong carrier relationships stays ahead of those changes before they impact your traffic. 60% of respondents in Bandwidth’s 2025 State of Messaging Report ranked deliverability as their top factor in choosing a messaging provider. That’s the bar your provider needs to clear.
“Being able to have that visibility through the tools that Bandwidth is providing makes us a better provider to our customers. And it’s super exciting, to be sure that deliverability is the best it can be.”
Day 0 is also the right time to audit your current Twilio messaging setup: document your active campaigns, registered numbers, and messaging formats in use. Voice and messaging run as parallel workstreams from here, each with their own checkpoints. You won’t have to wait until the voice migration is done to start the messaging inventory.
Days 1–30
Review your 10DLC campaign registrations and short code or toll-free configurations. Determine which campaigns are ready to move and which may require re-registration.
If you’re your own CSP, you can migrate approved, active campaigns to Bandwidth without re‑registering. So you’re ready to use the full potential of our high-throughput messaging quickly.
Either way, connect with your Bandwidth messaging expert early because campaign portability decisions made in week one can save weeks later.
Days 31–60
Update API endpoints to accept Bandwidth’s message delivery callbacks and verify delivery receipts map correctly to your database schema. Campaigns requiring re-registration can typically be approved in 2 to 3 business days with Bandwidth’s automated vetting.
Days 61–90
Cut over messaging traffic to Bandwidth. Confirm deliverability baselines against your Twilio benchmarks. Establish monitoring before you consider either workstream done.
Ready to evaluate messaging?
Talk to a messaging expert about your 10DLC setup, campaign registration, and which formats fit your use case best.
