OTP TESTING · FINTECH · MOCK SMS API · 2FA · COMPLIANCE
Fintech OTP Flows Need More Than a Test Phone Number
Zunoy Sandbox is a complete OTP testing environment for fintech teams — a mock SMS API for SMS OTP flows and a shared TOTP authenticator for 2FA flows, all in one workspace. Test OTP without SMS gateway costs, validate DLT compliance, and run shared team 2FA testing — without a real carrier, real credits, or a personal phone in the loop. Transaction verification, login 2FA, beneficiary addition, high-value transfer approval — every compliance-sensitive OTP flow tested safely before production.
Works with Twilio · MSG91 · Exotel · AWS SNS · Fast2SMS · Any REST SMS gateway · RFC 6238 compliant
If you're looking for any of these, this page is for you
Zunoy Sandbox is a mock SMS API and shared TOTP authenticator for fintech teams — test OTP without SMS gateway involvement, validate DLT compliance, and maintain a documented record of every test event.
Fintech OTP testing is held to a higher standard than most current approaches meet.
Real SMS Credits Burned on Every Test Cycle
Every OTP your app sends during development goes to a real carrier — costing real money on every sprint. Your team is spending thousands of rupees testing flows that haven't shipped yet, with no mock SMS API capturing what the carrier actually received. There's no way to inspect the full payload, validate the Sender ID, or confirm DLT template rendering — just a success response and a depleted credits balance.
One Phone. Five Testers. Compliance-Sensitive Flows.
Your QA team shares one phone to test transaction verification OTPs. Two testers need the code simultaneously. The OTP expires before the second tester gets to it. You're running compliance-critical fintech OTP testing with a workaround that doesn't scale and can't be audited.
No Audit Trail for OTP Test Flows
Regulators and auditors ask questions. Your current OTP testing setup — real SMS to a team phone, manually checked — leaves no documented record of what was tested, when, or by whom. If you're building in a regulated fintech environment, that's not just inconvenient — it's a compliance gap.
A mock SMS API for SMS OTP and a shared TOTP authenticator for 2FA — both in one fintech testing environment.
Replace your SMS gateway with a mock SMS API — zero credits, full visibility
Replace your SMS gateway URL with Zunoy's mock SMS API endpoint in staging. Every transaction verification OTP, login code, and beneficiary addition SMS lands in your SMS inbox — full payload visible, Sender ID confirmed, DLT template rendered. Test OTP without SMS gateway involvement. Zero credits consumed. Zero real numbers contacted.
TOTP 2FA without a personal phone — shared team access
Add your staging TOTP secret to TOTP Inbox. Every team member gets live 2FA codes in the browser simultaneously — no phone passing, no single point of failure, no testing stopping because one developer is in a different timezone. OTP testing without phone for your entire QA team, from any browser.
Validate Sender ID, DLT compliance, and message format
Every SMS that lands in Sandbox shows the complete payload — Sender ID, recipient number, message body, custom headers, timestamp. Confirm your Sender ID matches your DLT registration, your OTP format meets compliance requirements, and your message body matches your registered template — before a single real user receives a fintech OTP from a real carrier.
Documented test records — retained for your plan's window
Every OTP test event is captured in Sandbox with a full timestamp, payload, and Sender ID. Your team sees it simultaneously. The record stays in your inbox for your plan's retention window — a documentable trail of what was tested, when, and what the payload contained. Fintech OTP testing that leaves evidence.
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Configure your fintech OTP testing environment in under 10 minutes.
Configure Sandbox as your mock SMS API
In your staging environment config, replace your SMS gateway's base URL with Zunoy's mock SMS API endpoint. Your app sends the exact same API call — same headers, same Sender ID, same DLT template ID. The OTP lands in Sandbox instead of a real carrier. One environment variable. Zero code changes. Zero credits consumed from this point forward.
Add your TOTP secret to the shared authenticator
In TOTP Inbox, add your staging 2FA secret — via QR code or secret key paste. Live codes appear immediately, visible to every team member simultaneously. OTP testing without phone — your whole fintech QA team accesses the same live TOTP codes from any browser.
Trigger the OTP flow
QA runs a transaction verification flow — initiates a transfer above the threshold, triggers the OTP request. SMS OTP fires to the SMS inbox. TOTP code available in TOTP Inbox simultaneously. Both channels tested in the same session, from the same Sandbox account.
Validate the complete payload
QA confirms Sender ID matches DLT registration. Verifies OTP format and length. Checks message body against the registered template. Confirms custom headers are present and correct. Every field your app sent to the mock SMS API — visible and verifiable.
Multiple testers run simultaneously — documented
Second tester runs the beneficiary addition flow concurrently. Both flows captured in Sandbox with full timestamps and payloads. Every test event documented. Sign off with a retained record of what was tested, when, and what the payload contained.
Concrete example: An Indian digital payments company is preparing for a regulatory audit. Their QA team needs to demonstrate OTP flows were fully tested before production. Using Sandbox as their mock SMS API, every SMS OTP is captured with full payload — Sender ID, DLT template rendering, headers, timestamp. Every TOTP login test is run from the shared TOTP Inbox. The audit trail exists in Sandbox — no reconstructing from memory, no gaps in documentation.
Fintech OTP testing needs more rigour than current approaches provide.
Real SMS gateway in staging
Burns credits on every test cycle. Sends real OTPs to real numbers. No mock SMS API capturing what was sent — no way to inspect Sender ID, DLT template rendering, or custom headers. Not auditable.
Shared team phone
One device, one person. Testing stops when unavailable. No payload record. Not reproducible across testers. Definitely not suitable for compliance-sensitive fintech OTP testing.
Manual OTP extraction from logs
You see the OTP was generated. You don't see the Sender ID, DLT template rendering, headers, or what the carrier actually received. Not a substitute for a mock SMS API with full payload capture.
No structured OTP testing environment
No audit trail. No shared team access. No DLT validation. No documented record of what was tested. A compliance gap waiting to be found by an auditor or regulator.
Sandbox gives your fintech team a complete OTP testing environment — mock SMS API for SMS flows, shared TOTP authenticator for 2FA, full payload visibility, team-shared access, and a documented record of every test event.
BUILT FOR
Who uses Sandbox for Fintech OTP Testing
Fintech backend developers
Replace your SMS gateway with a mock SMS API endpoint in staging. Test every OTP flow — transaction verification, login, beneficiary addition — without a real carrier, real credits, or real users. Full payload visible. DLT compliance verifiable. Zero production risk.
QA engineers in regulated environments
Run complete fintech OTP test coverage — SMS and TOTP — with full payload records, shared team visibility, and documented timestamps. OTP testing without phone for your entire QA team. The rigour that compliance-sensitive fintech products require.
Security engineers
Validate that your OTP implementation is correct — Sender ID matches DLT registration, message format meets compliance requirements, header contract is enforced — before your mock SMS API environment gives way to a real carrier handling real financial transactions.
Other testing scenarios covered by Sandbox
OTP / 2FA Testing
Generate and verify TOTP codes in staging without real authenticator apps.
SMS OTP Testing
Validate OTP codes via SMS in staging without sending to real mobile numbers.
Webhook Testing for Payment Gateways
Inspect, replay, and debug incoming webhook payloads with a persistent request log.
The things developers ask about Fintech OTP Testing
What is the best way to test OTP without SMS gateway costs in fintech staging?
Replace your SMS gateway's base URL with Zunoy's mock SMS API endpoint in your staging environment config. Your app sends the same request — Sandbox receives it instead of a real carrier. Every transaction verification OTP, login code, and beneficiary addition SMS lands in your SMS inbox with the full payload visible — Sender ID, DLT template rendered, headers, timestamp. Zero credits consumed. Zero real numbers contacted. Configure it with one environment variable change.
Does Sandbox work as a mock SMS API for Indian fintech SMS providers?
Yes. Zunoy SMS Inbox works as a mock SMS API for any REST-based SMS gateway — MSG91, Exotel, Fast2SMS, Textlocal, and any other Indian SMS provider. Replace the base URL in your staging config — same payload structure, same headers, same Sender ID. Works immediately with no code changes.
Can I validate DLT template compliance without a real carrier?
Yes. Create your DLT templates in Sandbox with your registered message body and variable placeholders. Your app sends the template ID and variable values — Sandbox resolves and renders the full message exactly as a real carrier would. Validate template ID, variable rendering, and message format compliance — without carrier involvement or approval processes. See SMS Inbox for full details.
Is there an audit trail for fintech OTP test flows?
Every OTP event captured in Sandbox includes a full timestamp, complete payload, Sender ID, and header record — retained for your plan's retention window. This provides a documentable record of what OTP flows were tested, when they were tested, and what the complete payload contained. Suitable for demonstrating pre-production OTP test coverage in regulated fintech environments.
How does OTP testing without phone work for TOTP-based 2FA?
Add your staging TOTP secret to Zunoy TOTP Inbox — via QR code or secret key. Every team member accesses live 2FA codes from any browser simultaneously. No phone. No personal authenticator app. No single point of failure. Your entire fintech QA team tests TOTP login flows in parallel — from any browser, any location. See TOTP Inbox for full details.
Fintech OTP testing that meets the standard your product and your regulators require.
Configure your mock SMS API and shared TOTP authenticator in under 10 minutes. Full payload visibility, DLT compliance validation, team-shared access, and documented test records — zero credits consumed.
Mock SMS API — one endpoint change, full payload capture
OTP testing without phone — shared TOTP for the whole team
DLT template validation without carrier involvement
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