TOTP with SMS 2FA fallback
TOTP with SMS 2FA fallback, built on a proven open-source foundation and adapted to how your business already works.
This is the outcome, not a promise of one
A worked example of exactly what this build does once it is live in your business.
- 00:00Signup attempt from a number we have never seen.
- 00:01Number checked: prepaid mobile, carrier known, not a virtual range.
- 00:03Code sent. Rate limits applied by number, account and address.
- 00:19Verified. Account created.
- 00:22Second attempt, same number, third account today. Blocked.
Outcomes
- Fake signups and throwaway numbers filtered before they cost you
- A second factor your customers can actually use
- Fewer password resets landing on support
Identity assurance
A code, push or cryptographic challenge is issued to a channel the customer controls, then checked with strict rate limits and short expiry.
- Pick the primary channel by delivery rate in your actual customer base
- Set the fallback order and the retry backoff
- Rate limit by number, by account and by IP
- Log every attempt for the audit trail without logging the code itself
Four things that are true of every build
The terms are the same whether you spend two thousand dollars with us or twenty.
A fixed price
Quoted before we start, naming what it does and what it will not do. It does not move unless you change the scope in writing.
Proof before launch
You sign off on real output from your own cases, not a demo video. If it does not convince you, it does not go live.
Everything in your name
Accounts, numbers, data, repository. Nothing switches off if you stop working with us, and there is no migration to negotiate.
30 days of fixes free
Anything that does not behave the way we said it would gets fixed at our cost for the first 30 days, whether or not you take the managed plan.
What is in the box
The whole build, on one page. No line item appears later that is not here.
| Product line | Verification & identity |
|---|---|
| Implementation pattern | Identity assurance |
| Best fit | any business with customer accounts, portals, checkouts or staff logins |
| Runtimes available | javascript |
| Foundation | Open-source reference implementation, maintained by Twilio itself, which is the strongest signal a sample will still work next year — javascript |
| Platform services | Twilio Verify for the channel and rate limiting, Lookup for number intelligence, and a thin backend we run so secrets never sit in your app. |
| Typical build | About one week to a staging number, then live monitoring before sign-off |
| Build price | ~$2,500 fixed scope |
| Run price | ~$390/mo managed, platform usage billed at cost |
| Compliance handled | Consent capture, sender identification, automatic opt-out, logging and retention |
Related builds
Same pattern or same product line.
Add User Verification to your App
A code, push or cryptographic challenge is issued to a channel the customer controls, then checked with strict...
Conference Line with Phone Verification
A code, push or cryptographic challenge is issued to a channel the customer controls, then checked with strict...
Customer Authentication Flex Plugin
A code, push or cryptographic challenge is issued to a channel the customer controls, then checked with strict...
Get this built for your business
Fixed-price scope, about a week to a working staging number, and we run it afterwards if you want.