Each guide answers one question: how a sign-up asks for your number, which number fits which app, and what to do when nothing arrives. Short, with steps and tables instead of long text.
Basics
- Authenticator app vs. SMS codeHow a Google Authenticator code is made, how it compares with an SMS code, how to switch without locking yourself out, and when a text is still the only way.
- Backup codes explainedWhat a backup code is, where Google and Steam keep them, how to store them safely, and why they still work after you change or lose your phone number.
- Burner numbers explainedA burner number can mean three different things. Which kind fits sign-up codes, dating, selling or calls, and why free disposable numbers fail at big apps.
- Entering a number with country codePlus, country code, number without the leading zero. Examples for the USA, Mexico, Spain and more, special cases, and the mistakes behind invalid number errors.
- Non-VoIP numbers explainedMobile, landline, fixed and non-fixed VoIP compared. How apps detect the line type, which ones are strict, and how to pick a number that gets the code.
- Number already in useWhy apps say "this phone number is already in use", which services allow one number on several accounts, and how to set up a second account cleanly.
- Receive SMS on your computerHow to receive SMS on a PC or Mac with your own number through phone pairing, why no website can do it, and when a separate number is the better fit.
- Second phone number optionsFive ways to get a second phone number compared: second SIM, eSIM, calling app, prepaid phone or a one-time number. Which fits calls, chats or sign-up codes.
- Verification by call instead of SMSWhy WhatsApp, Telegram, Google, Apple and others offer a call instead of an SMS code, what to check when neither arrives, and which numbers cannot take calls.
- What OTP meansOTP means one-time password: a short code that works once. What an OTP text looks like, how it differs from 2FA and a PIN, and why you never share it.
- Which apps ask for your number againWhich apps check your phone number again after sign-up, what happens when that number is gone, and which number to use for which kind of account.
- Which apps require a phone numberWhen 62 popular apps ask for your phone number, whether by SMS or call, if they ask again later and if one number allows only one account. From our fact sheets.
Apps and services
- Airbnb phone verificationWhat the Airbnb verification code is, how the 4-digit SMS check works, what to do when it does not arrive, and when hosts and guests see your number.
- AliExpress verification codeWhere AliExpress sends its verification code, why it may not arrive by SMS, when an e-mail sign-up is the easier way, and how to add a number later.
- Amazon account without a phone numberAmazon accounts can rest on an email address or a mobile number. What Amazon asks for at sign-up, when a number comes in anyway, and how to keep access.
- Apple Account without a phone numberWhat Apple asks for when you create an Apple Account (Apple ID), whether the phone number can be skipped, and which number to use as your trusted number.
- Badoo phone verificationHow Badoo phone verification works by SMS or call, why a code gets refused, what "number already in use" means, and how to keep your number from members.
- Bigo Live phone verificationHow Bigo Live uses your phone number at sign-up, why the verification code may not arrive, and signing up with a number from another country.
- BiP activation codeHow BiP activates your account by SMS or call, what to check when the activation code does not come, and using BiP with a number from outside Turkey.
- BlaBlaCar phone verificationWhy BlaBlaCar needs your phone number to publish or book a carpool, how the 4-digit SMS check works, and when your number goes to the people you travel with.
- Bumble phone verificationCan you use Bumble without a phone number? How the SMS and call check work, what to do when the code does not arrive, and how to keep your number from matches.
- ChatGPT phone numberDoes ChatGPT need a phone number? When OpenAI asks for one, which numbers it refuses, the three-use limit per number, and what to do if no code arrives.
- Claude phone verificationWhy Claude asks to verify a phone number, which numbers Anthropic refuses, the three-accounts-per-number limit, and what to do when the code does not arrive.
- Discord phone verificationWhy Discord or a server asks you to verify a phone, how to add one step by step, why some numbers are refused, and how many accounts one number can verify.
- Email without a phone numberWhich email providers ask for a phone number at sign-up: Gmail, Outlook, Yahoo and Proton compared, the allowed alternatives, and how to secure the inbox after.
- Facebook without a phone numberYes: Facebook lets you sign up with an email address. How to do it, when Facebook asks for a number anyway, and how to keep your number off your profile.
- Free virtual number for WhatsAppWhy free virtual numbers rarely get a WhatsApp code, how a public inbox lets strangers take over your account, and how a private number works instead.
- Google account without a phone numberHow to make a Google or Gmail account without a phone number, what to do when Google insists on one, and how to secure the account without a phone.
- Hinge verification codeWhy Hinge's SMS code does not arrive, the 24-hour lock after failed tries, whether you can use Hinge without a phone number, and why some numbers are refused.
- imo verification codeHow imo verifies your number by SMS, what to check when the imo verification code does not arrive, and how to sign up with a number from another country.
- Instagram without a phone numberInstagram accepts an email address instead of a phone number. Why it may still ask for one, how to log in without your phone, and how private your number stays.
- Naver without a Korean numberCan foreigners sign up for Naver without a Korean phone number? What sign-up asks for, what identity verification unlocks, and the passport option since 2026.
- Number for WhatsApp BusinessWhat WhatsApp Business needs from a phone number, how SIM, landline, virtual line and one-time number compare, and why a business needs one that stays.
- OLX phone verificationWhy OLX asks for your phone number, how to verify it, how to keep it out of your listings, and the code scam that targets OLX sellers.
- Reddit and phone numbersReddit does not require a phone number. When it asks for one, what the code is for, how to add or remove a number, and the trap with phone-only accounts.
- Sahibinden phone verificationWhy Sahibinden needs a verified Turkish mobile number, how to add it, why foreign numbers fail, and how to keep your number out of listings.
- Second Telegram accountHow to run a second Telegram account in the same app, why every account needs its own phone number, and how to keep work and private chats apart.
- Second WhatsApp accountHow to add a second WhatsApp account on the same phone, when WhatsApp Business is the better choice, and where the second number should come from.
- Snapchat without a phone numberSnapchat needs one verified contact, and an email address will do. When a phone number comes into play anyway, and how to keep yours out of friend suggestions.
- Steam Guard and phone numberSteam Guard codes come by e-mail or from the app; texts are for your phone number. How to add one, why the SMS may not arrive, and which numbers Steam refuses.
- Telegram without a phone numberTelegram needs a mobile number to sign up, but nobody has to see it. How to register with a number you do not hand out, then hide it behind a username.
- Temu and SHEIN verification codesWhy Temu and SHEIN text you a verification code, what to check when it does not arrive, what an unrequested code means, and how to keep your own number private.
- TikTok verification codeWhere TikTok sends its six-digit code, what to check when it does not arrive, what a code you never asked for means, and how to get past too many attempts.
- TikTok without a phone numberYou can sign up for TikTok with an email address. What decides whether you can send messages, how to log in without your phone, and when adding a number helps.
- Tinder and your phone numberWhy Tinder asks for a phone number, whether you can sign up without one, the catch with a temporary number, and how to keep your number away from matches.
- Twitch phone verificationWhy Twitch asks you to verify a phone number, how to add one, why the code may not arrive, and the five-accounts rule that links every account on a number.
- Uber verification codeHow Uber checks your number with a four-digit code, why the text does not arrive, when to take the call option, and why Uber asks again on a new phone.
- Vinted phone verificationWhere Vinted verifies your phone number, why the four-digit code fails, the two-hour lock after wrong numbers, and the one-number-per-account rule.
- WeChat verificationWhy WeChat asks for extra verification, how the friend check works, what to do when the SMS code does not come, and how to sign up without a Chinese number.
- WhatsApp on a PC, tablet or second phoneUse your own WhatsApp on a computer, tablet or second phone with no SIM and no SMS code: link it by QR code or an eight-character code from your main phone.
- WhatsApp with a landline numberWhatsApp accepts a landline only in WhatsApp Business, verified by a phone call. The steps, the drawbacks of a landline account, and the alternatives.
- WhatsApp without a SIM cardWhatsApp needs a phone number, not a SIM in the phone. Three ways to register without a SIM, the steps with a one-time number, and what happens later.
- Wolt, Glovo, Deliveroo verificationPhone verification in Wolt, Glovo and Deliveroo: why the code is late, what each app's help says, and when couriers and restaurants see your number.
- X (Twitter) phone verificationWhen X asks to verify a phone number, where to add or remove it, why the code may not arrive, and how to keep the number from making your account findable.
- Yahoo Mail without a phone numberCan you make a Yahoo account without a phone number? What Yahoo asks for at sign-up, why the code may not arrive, and how to keep access later.
Countries
- Australian numbers for verificationAustralian mobiles start with 04 and have ten digits. How to write one as +61, the ways to get one from abroad, and how a code on an Australian number works.
- Brazilian number from abroadHow a Brazilian mobile number is built (+55, DDD, 9 digits), which apps people want one for, and how to receive a code on a +55 number from abroad.
- Canadian phone number from abroadWhat a Canadian number looks like, all 58 area codes by province, your four options from outside Canada, and how to get one verification code on a +1 number.
- Choosing the country for your numberHow to pick the country for a verification number: what the success rate means, why it stops at 95 %, price versus rate, and when to switch country.
- French phone numbers (+33)How French phone numbers are built (ten digits, 06 and 07 for mobiles), how to write one as +33, and how to get a French number for a verification code.
- German phone number from abroadHow a German mobile number is built (+49 15x, 16x, 17x), which services expect one, your options from abroad, and how to get one code on a German number.
- Indian phone number for an OTPHow an Indian mobile number is built (+91 and ten digits), which apps expect one, how to get an Indian number from abroad, and how to receive one OTP on it.
- Mexican phone numbers (+52)How a Mexican number is built since the 2019 dialling change, how to write +52 in WhatsApp, and when a Mexican number for one verification code makes sense.
- Portuguese phone numbers (+351)Portuguese numbers have nine digits: mobiles start with 9, landlines with 2. How to write them internationally and how to get one before you arrive.
- Spanish phone number (+34)How a Spanish mobile number is built (+34, nine digits, starting with 6 or 7), how to write it in apps and forms, and how to get one from outside Spain.
- Turkish phone numbers (+90)How a Turkish mobile number is built, how to write +90 correctly in apps, ways to get a Turkish number from abroad, and when a number for one code is enough.
- UK phone number from abroadWhat a UK mobile number looks like (+44 7…), which 07 numbers are not mobiles, your options from abroad, and how to receive one code on a UK number.
- US phone number from abroadWhat a US number looks like (+1, area code, ten digits), your options from outside the US, why some US numbers are refused, and how to get one code on one.
Privacy and security
- Fake numbers for verificationA made-up number never receives a code. What people mean by a fake number for verification, good reasons to keep your own private, and where the line is.
- Hide your number in messengersWho can see your number on Telegram, Signal and WhatsApp, the exact settings that hide it, how usernames help, and what you cannot hide in each app.
- Kleinanzeigen phone numberWhy Kleinanzeigen verifies your phone number by SMS, which numbers it accepts, how to keep your number out of your ads, and the scam that asks for your code.
- Messengers without a phone numberWhich messengers need a phone number, which hide it behind a username, and which work with none. A table, the trade-offs, and what to do if yours insists.
- Proton Mail human verificationWhat Proton's human verification is, the CAPTCHA, e-mail and SMS options, what Proton keeps of your number, and what to do when no option works.
- Selling online without your numberWhich marketplaces ask for your number, how to sell without showing it to buyers, and the "send me the code" trick that takes over sellers' accounts.
- Signal without sharing your numberSignal needs a number to register, but nobody has to see it. How usernames hide it, which number to register with, and what the PIN and registration lock do.
- SMS 2FA and SIM swap protectionHow SMS codes protect an account and where they fall short, what a SIM swap is, five steps that make one harder, and why temporary numbers never belong in 2FA.
- Unrequested verification codesWhy a confirmation code arrives that you never asked for, how the 'send me the code' scam on Marketplace works, and what to do right now if you shared one.
- What someone can do with your numberThe real risks when a stranger has your phone number, from spam to SIM swapping, where numbers leak, and which accounts should get your main number.
When the code does not arrive
- "Invalid phone number" errorsWhy an app says "invalid phone number" or "number not supported": format mistakes, countries the app does not serve, line types and blocked ranges.
- Amazon OTP not receivedWhich one-time password Amazon is sending, why the OTP text does not arrive, how to unblock Amazon's short code, and what to do when 2-Step Verification fails.
- Apple verification code not sendingWhere Apple sends your six-digit Apple Account code, what to check when it does not arrive, how to get it by call, and how to keep your trusted number current.
- Bolt verification codeHow Bolt verifies a rider's number, why the SMS code may not arrive, how long to wait, and why Bolt asks for the code again on a new phone.
- eBay phone verificationWhy eBay asks for your phone number, why the code fails (15-minute expiry, closed sign-in page, landlines), and your 2-step verification options.
- Facebook code not receivedWhich Facebook code you are waiting for, what to check when the SMS does not come, how to confirm by email instead, and what to do when login codes fail.
- Gojek OTP not arrivingWhy the Gojek OTP does not arrive (OTP Gojek tidak masuk): SMS or WhatsApp, the 30-second wait, login links that expire, and why Gojek asks again.
- Google verification code not receivedGoogle sends its code by text, by call or as a prompt on your phone. What to check when it does not arrive, when to wait, and when a different number helps.
- Google: number cannot be usedWhat Google's message means, the causes Google itself names, what to try in which order, and how to pick a number that gets through.
- Grab OTP not arrivingGrab logs you in with a one-time code by SMS. What to check when the Grab OTP does not arrive, signing up with a foreign number, and why Grab asks again.
- Instagram code not arrivingWhere Instagram sends its six-digit code at sign-up and login, what to check when it does not come, other ways to get it, and what to do after too many tries.
- LINE verification codeHow LINE verifies a new account, where the code arrives by text or call, what to check when it does not, and how sign-up works outside its five phone regions.
- LinkedIn verification codeWhy a LinkedIn verification code does not arrive, the 24-hour limit after too many requests, two-step verification without SMS, and who sees your number.
- Microsoft or Outlook code not receivedWhere Microsoft sends security codes for Outlook, Hotmail and Xbox, nine common reasons they go missing, and how to add a sign-in method that works.
- Shopee and Lazada OTP not receivedWhy a Shopee or Lazada OTP does not arrive, what Shopee itself tells you to check, and how to sign up with a number when your own is not an option.
- Snapchat verification codeWhere Snapchat sends its confirmation code, what to check when it does not arrive, how to switch to a call or email, and how to change your number.
- Telegram code not receivedTelegram often sends the login code into the app on another device, not by SMS. Where to look, how to get it by SMS or call, and what changes on a new number.
- Tokopedia OTP not receivedWhy the Tokopedia OTP does not arrive (kode OTP tidak masuk), how to type an Indonesian number correctly, and signing up from outside Indonesia.
- Too many attempts: try again laterWhy apps lock the code request, the waiting times WhatsApp, Snapchat, Discord and Google actually state, what makes it worse, and how to try again properly.
- Verification code not receivedWhy an SMS verification code does not arrive, how to tell the causes apart from what you see on screen, and what to do next, step by step.
- Viber activation codeHow Viber activates a number by SMS, call or flash call, what "Activation failed" means, when to wait 24 hours, and how Viber works on desktop and tablet.
- WhatsApp code not receivedWhatsApp code not arriving? Check the number format, signal and SMS filters, wait out the timer, switch to a call or email, and know what each error means.