Codex Phone Verification: How to Receive the Login SMS Code (2026)
Need quick Codex verification codes? Start your Codex verification journey now
When Codex login demands phone verification, a one-time number from SMS-Act receives the SMS code: pick the OpenAI service, choose a country, get a number, enter it on the Codex login page, and read the code in your dashboard. Flat 8 credits per attempt, automatic refund on failure, 160+ countries, Stripe top-ups. This guide covers the login step-up on Codex CLI, the IDE extension, and Codex web; for first-API-key verification see the OpenAI SMS verification guide.
About Codex
Codex is OpenAI's agentic coding tool for developers, available as Codex CLI, an IDE extension, a Codex mode in the ChatGPT desktop app, and Codex web. It signs in with your ChatGPT account — per OpenAI's current documentation, every ChatGPT plan including Free can use Codex, with usage limits tiered by plan. Since 2026, large numbers of developers have hit a phone verification wall when signing in to Codex — even when the same account never needed verification for ChatGPT. That is exactly why searches for Codex phone verification have surged.
Which Codex scenarios trigger phone verification?
Based on public GitHub issues (openai/codex) and OpenAI Community reports, the typical triggers are:
- First Codex CLI login: running
codexopens a browser auth flow that redirects toauth.openai.com/add-phone(currently frequent; paid accounts are affected too) - IDE extension / desktop app login: first authorization of the Codex extension in VS Code, Cursor, or the ChatGPT desktop app's Codex mode
- New device / reinstall / first Codex use on an older account: signing in from a new machine or IP, or retrying after a failed browser callback
- Risk signals: shared VPN exits, datacenter IPs, unusual browser fingerprints
The same user often finds one account challenged while another is not — proof that this is a risk-based step-up, not a blanket requirement. OpenAI's support account has explained the rationale: Codex interacts directly with your codebase, so it needs stronger security.
Two distinctions worth keeping straight:
- Codex login verification ≠ API key verification. The former is a login step-up; the latter is a one-time check when generating your first API key on platform.openai.com (officially limited to 3 uses per number). Both are sent by OpenAI, and the receiving flow is identical.
- Codes arrive only via SMS or WhatsApp — never email or voice call, per OpenAI's official documentation. OpenAI publishes an official WhatsApp-channel country list of 12 countries (India, Indonesia, Malaysia, Türkiye, UAE, Egypt, Israel, Nigeria, Pakistan, Saudi Arabia, Ukraine, Vietnam). SMS-Act one-time numbers receive SMS only — picking a number outside those 12 countries sharply lowers the chance of being routed to WhatsApp.
Why use SMS-Act for Codex verification codes?
- Real carrier numbers: OpenAI officially does not support landlines, VoIP, Google Voice, or premium numbers — and states it has expanded VoIP blocking internationally. SMS-Act numbers come from real mobile carriers, so they are not in the rejected VoIP category
- Global coverage: 160+ countries and regions, easy to match with your IP location
- Instant delivery: codes usually appear within 30 seconds
- Transparent pricing: flat 8 credits per attempt, automatic credit refund on failure
- Privacy: no need to expose your personal number
Step-by-step: receiving the Codex verification code
Step 1: Register on SMS-Act and top up
- Visit SMS-Act
- Register with email + password, then activate via the confirmation link
- Top up via Stripe (16 credits recommended, leaving room for one retry)
Step 2: Get a receiving number
- Search for and select the OpenAI service (Codex codes are sent by OpenAI — there is no separate Codex entry)
- Choose a country: prefer one that matches your current IP and is outside OpenAI's 12-country WhatsApp list (Philippines, Brazil, UK — see the table below)
- Click "Get Number" — a one-time temporary number is assigned instantly (8 credits, valid 15 minutes)
Step 3: Complete verification on the Codex login page
- Return to the page that triggered verification: the Codex CLI auth page, IDE extension login, or account check page
- Enter the SMS-Act number (mind the country code)
- Confirm the channel shown is SMS / text message, then send the code
- Read the code in your SMS-Act dashboard (usually within 30 seconds)
- Enter it to finish login; if it times out, cancel the number (credits auto-refund) and retry with another country
💡 For CLI users
Codex CLI login completes in the browser (the terminal prints an auth link), and phone verification happens on that browser page. Finish verification in the same browser and network environment that initiated the login — switching IP or browser mid-flow can invalidate the session and force a fresh login.
Not receiving the code? Check in this order
- Channel check: does the page only show "Send via WhatsApp"? The WhatsApp channel requires a number already registered on WhatsApp and online — no SMS receiving platform can accept it. Cancel the number (credits auto-refund), switch country and network environment, and retry once the SMS channel is back.
- Timing: wait up to 3 minutes on the SMS channel, then cancel and retry. Do not spam Resend — per openai/codex maintainers and community reports, repeated requests are silently throttled (the page shows no error but stops sending); wait 15–20 minutes before the next attempt.
- Switch country: prefer ranges outside the official WhatsApp list (Philippines, Brazil, UK). German-speaking ranges draw frequent WhatsApp-only reports — use with caution.
- Network environment: avoid free VPNs and datacenter IPs; keep "IP country = number country"; no more than 3 attempts per IP per 24 hours.
- Fingerprint isolation: an incognito window in a browser already signed in to another ChatGPT account does not isolate the fingerprint — use a clean browser profile.
Country selection reference (2026 field data)
| Priority | Recommended countries | Rationale | Overall success rate |
|---|---|---|---|
| ⭐⭐⭐⭐⭐ | Philippines, Brazil, UK | Outside the official 12-country WhatsApp list; stable SMS channel | 90%+ |
| ⭐⭐⭐⭐ | USA, Canada, France | Outside the list; good community feedback | 85%+ |
| ⚠️ Caution | India, Indonesia, Malaysia, Türkiye, etc. | On the official WhatsApp list — may be routed to WhatsApp | Channel-dependent |
| ⚠️ Caution | Germany, other German-speaking regions | Off-list yet with community reports of WhatsApp-only routing (openai/codex #25798) | 70%+ |
SMS-Act uses flat pricing platform-wide (8 credits per attempt), so pick countries purely by success rate — no price trade-off needed. Failed orders refund credits automatically.
Frequently asked questions
Q: Which service do I pick on SMS-Act for Codex?
A: The OpenAI service. Codex verification codes are dispatched by OpenAI, shared with API key verification and ChatGPT risk checks — same sender, same receiving entry.
Q: Why does Codex ask for phone verification when ChatGPT never did?
A: Public GitHub issues (openai/codex #25798, #25737) and OpenAI Community threads document a phone verification step-up on the Codex login path — paid accounts included. It is a risk-based check for the Codex scenario, not a sign of an account problem.
Q: How much does one verification cost? What if it fails?
A: Flat 8 credits per attempt, no country-based pricing. If no code arrives, the 8 credits are automatically refunded to your balance; retry with another country or number. Top-ups via Stripe.
Q: How many accounts can one number verify?
A: OpenAI's official documentation states a number can be used for phone verification at most 3 times, with no exceptions; community reports show Codex logins hit the same pool ("number already associated with the maximum number of accounts" errors). OpenAI also does not support changing a bound number, and numbers are released only 30 days after account deletion. Use a separate number per account.
Q: Can Google Voice or another VoIP number pass Codex verification?
A: No. OpenAI officially rejects premium numbers, landlines, Google Voice and other VoIP numbers, and has expanded VoIP blocking internationally. SMS-Act supplies real carrier numbers, which are not in the rejected category.
Q: Can I reuse the number later?
A: SMS-Act numbers are one-time temporary numbers recycled after the 15-minute window. If OpenAI later asks you to re-verify the same number, it may no longer be available — bind a long-term number of your own in account settings, or repeat this flow when needed.
Q: Which ChatGPT plan does Codex need? Does it matter for verification?
A: Per OpenAI's current documentation, every plan including Free can use Codex, with usage tiered by plan. No published correlation exists between plan level and verification triggers — paid accounts get challenged too.
Related guides for AI coding tools
- OpenAI SMS verification guide - first API key and account risk checks
- ChatGPT SMS verification guide - ChatGPT account registration
- Cursor phone verification guide - Cursor editor sign-up
- Claude Code SMS verification - Anthropic Claude Code checks
- Gemini verification code guide - Google Gemini verification
- Codex Computer Use guide - what Codex agents can do
Finish Codex phone verification in minutes
When Codex CLI or the IDE extension blocks you at phone verification: register on SMS-Act → top up via Stripe → select the OpenAI service and a country → get a number and receive the code. The whole flow usually takes a few minutes, and failed attempts refund automatically.
Disclaimer
This platform is designed to support development testing, business verification, and international service scenarios, helping users complete processes in a reasonable and compliant manner.
Users are expected to ensure that their use of the service complies with applicable laws, regulations, and the policies of third-party platforms. The platform does not participate in or control how the service is used.
Accounts associated with abnormal or improper usage may be subject to restrictions in accordance with platform policies.
Users must be at least 18 years old and acknowledge that they are fully responsible for their own use and any resulting outcomes. If you do not agree with these terms, please discontinue use of the service.
Start now - receive your Codex code
Last updated: 2026-08-03 | Next review: 2026-11 Pricing: all verifications are a flat 8 credits per attempt, auto-refunded on failure. Stripe only.
Sources: OpenAI Help — Phone verification, OpenAI — VoIP/Google Voice policy, OpenAI — phone number use limit, OpenAI — WhatsApp country list. The Codex login step-up is documented from public GitHub issues (openai/codex #25798, #25737, #25749) and OpenAI Community threads; it is not an official OpenAI policy statement.