How to migrate SMS marketing software
A salesperson will tell you switching SMS platforms is a list export and an afternoon. It is not. The hard part is not the contacts — it is the number that has to keep delivering and the consent records that keep you on the right side of the TCPA. Here is the honest switching-cost reality: what transfers, what breaks, and a realistic timeline for changing SMS providers without losing your list or your sender.
The list is the easy part. The number and the consent are not.
Let me puncture the sales pitch. Exporting your subscribers to a CSV and importing them elsewhere takes minutes — and means almost nothing on its own. SMS is a regulated, carrier-gated channel, so two things decide whether your migration is clean or a disaster, and neither is the contact list.
First, the sending number. Since February 2025 carriers block unregistered A2P traffic from 10-digit numbers outright — messages do not get filtered, they simply never arrive — so a number that is not registered and provisioned on the new platform sends to nobody. A dedicated short code transfers on the carriers' timetable, in weeks. Second, consent. Under the TCPA you need prior express written consent, and the proof of it — source, timestamp, the language each subscriber agreed to — is what makes a contact lawfully messageable. Lose that in the move and you face damages of $500–$1,500 per message, or you re-collect consent and watch your list shrink. Plan the migration around those two realities, and pick the destination using how to choose SMS marketing software.
The six phases of an SMS migration
The highest-leverage decision is timing, and timing is dictated by your sending number. A dedicated short code transfer is a carrier process measured in weeks, not days; a 10DLC long code means re-registering your brand and campaign with The Campaign Registry through the new provider (brand 1–3 days, campaign 2–7, roughly two weeks end-to-end); a toll-free number needs re-verification. Map that path first and set the cutover date after it, never before. Since February 2025 carriers block unregistered A2P traffic outright, so an unregistered number on launch day sends nothing.
This is the step that separates a clean migration from a TCPA exposure of $500–$1,500 per message with no cap. Your subscribers' value is not the phone numbers — it is the proof of prior express written consent attached to each: the opt-in source, timestamp, and what they agreed to. Export that consent metadata in full from the old platform and store it, because if it does not transfer you cannot lawfully message those contacts on the new one, and re-collecting consent shrinks your list overnight.
Now execute the number path you mapped. Porting a long code or re-registering 10DLC re-establishes your throughput tier and carrier trust from a lower starting point; a short code transfer runs on the carriers' timetable and cannot be rushed. Do not cancel the old number until the new one is fully provisioned and sending, or you create a gap where inbound keywords and replies vanish. Treat this as the critical path the rest of the plan waits on.
Automations, keyword responders, templates, segments and A/B tests do not migrate — they are rebuilt in the new tool. So are your integrations: the Shopify, e-commerce and email connectors re-authenticate, and any abandoned-cart or post-purchase flow has to be re-wired and re-tested. Recreate your opt-out handling first and verify it works, because a missed unsubscribe is both a compliance failure and a fast way to lose carrier trust on a fresh number.
A new or re-registered number starts with limited throughput and no reputation. Do not blast your full list on day one. Send to a small, highly engaged segment first, confirm delivery and opt-out handling end to end, and ramp volume as the carrier raises your limits. This warm-up is exactly where rushed migrations break — high volume from a cold number gets filtered or blocked, and you torch deliverability for the whole list to save a week.
Once the number is live, flows are rebuilt and warm-up is clean, switch fully — but keep access to the old platform until you have exported message history, analytics and the consent archive, and through at least one full billing and reporting cycle. Those records are your evidence if a consent or delivery question ever arises, and they live only in the old tool. Cancel after you have them in hand, not before.
The export gotchas, named
Some platforms make leaving harder than others, and we score exit cost. The deepest lock-in sits with the ecosystem-bound tools: leaving Klaviyo SMS usually means untangling it from Klaviyo email and flows at the same time, and Postscript is wired tightly into Shopify, so a migration is really two migrations. Attentive runs a managed, enterprise-contract model around its short code — powerful, but the short code and the contract are the friction on the way out. The lighter long-code tools cut the other way: SimpleTexting, TextMagic and Sakari are easier to leave precisely because there is less ecosystem and no short code to transfer. Weigh the exit cost before you sign, not after.
No — and it is harder than email or most SaaS migrations for one reason: the phone number and the consent records. Moving your contact list is trivial; moving it lawfully, with proof of opt-in intact, and standing up a sending number that carriers will actually deliver from, is the work. Underestimate the number and you launch to silence; underestimate consent and you risk TCPA damages of $500–$1,500 per message. Plan around those two, not around exporting a CSV.
The phone numbers usually export fine; the consent metadata is the risk. TCPA requires prior express written consent, and the proof of it — source, timestamp, the language people agreed to — is what makes a contact legally messageable. Export that consent archive in full before you migrate. If it does not carry over, you cannot message those subscribers on the new platform until you re-collect consent, which always shrinks the list.
Sometimes, but not instantly. A dedicated short code can transfer between providers, but it is a carrier process measured in weeks, so it must be the first thing you start, not the last. A 10DLC long code generally means re-registering your brand and campaign with the new provider — roughly two weeks end to end — and a toll-free number needs re-verification. Whichever you have, never cancel the old number until the new one is provisioned and sending.
A small business on a 10DLC long code can realistically switch in two to three weeks, most of it waiting on brand and campaign registration. A brand running a dedicated short code should budget two to three months, because the short code transfer runs on the carriers' timetable and the rest of the plan waits on it. Add a warm-up period on top before you trust the new number with full volume.
No. Keep it until the new number is fully live, your flows are rebuilt and tested, and you have exported message history, analytics and — most importantly — the consent archive. Those records are your evidence if a consent or deliverability question ever surfaces, and they exist only in the old tool. Cancelling early to save one month's fee is how brands lose the proof they need exactly when a regulator or carrier asks for it.
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