Once you have added a Passkey on MPChat, you have three faster ways to sign in: enter your account and let your local Passkey verify, scan a cross-device QR from another phone, or skip typing entirely with one-tap "Continue with Passkey". This article explains all three flows, when each one shows up, and what every error message means.
Sign in to MPChat with a Passkey
Passkey login replaces the SMS / email code or password step you used to see right after entering your account. The legacy code-based login still works in case your Passkey is unavailable — pick the flow that fits your situation.
Flow A — Same-device Passkey login (most common)
On the MPChat sign-in screen, enter your account (phone number or email).
Tap Sign in. MPChat checks the server: if this account has a Passkey, the system Passkey sheet pops up.
Confirm with Face ID, Touch ID, or your device PIN — that is the entire verification.
This is one continuous step (no separate "(1/2)" indicator) — once verified, you go straight into MPChat. If you also turned on phone, email, or Google under Me > Security Center > Two-Factor Authentication (2FA), after the Passkey check you still have to complete those items in order before you can sign in. For example, if all three are on, you verify the Passkey and then phone, email, and Google in turn. To verify fewer items, turn off the ones you do not need on the 2FA page — keep at least one.
Flow B — Cross-device Passkey login (use another phone's Passkey)
If you are signing in on a phone where you have not stored your Passkey (e.g. your spouse's tablet, a friend's borrowed phone), the system sheet offers Use a passkey on a different device. The flow:
Tap that option on the device you want to sign in on.
The system shows a QR code.
Open the camera on the phone that does have your MPChat Passkey, point it at the QR, and confirm with Face ID / fingerprint / PIN over there.
The first device automatically completes sign-in.
This works because Passkey assertion is signed on the trusted phone but transmitted via Bluetooth + cloud relay; nothing about your Passkey is copied to the borrowed device.
Flow C — One-tap "Continue with Passkey" (no account typing)
On the sign-in screen, the bottom of the form has Continue with Passkey. Tap it and the OS shows the Passkey sheet directly — no need to type your phone number or email first.
If your phone has multiple MPChat Passkeys (rare — typically a family-shared device), the OS asks which account to use.
Once you confirm, the corresponding MPChat account is signed in.
You can also tap Use a passkey on a different device here to fall back to Flow B.
If the Passkey check fails
MPChat shows a single error dialog covering most failure types: "Passkey verification failed. Please try again or switch the verification method." Tap Got it to dismiss. Common causes:
You closed the system sheet by mistake → just retry.
Face ID / Touch ID failed several times in a row → wait a few seconds and retry, or fall back to device PIN.
The cross-device QR scan timed out → tap Use a passkey on a different device again to regenerate the code.
The other phone's Passkey is for a different MPChat account → make sure both devices are pointing at the same account.
Special errors during one-tap login
"Account does not exist or Passkey has been removed" — the Passkey on this device is stale (the account was deleted, or the Passkey was reset). See How to reset your Passkey.
"No Passkey for MPChat is stored on this device" — there is no MPChat Passkey on this phone yet. Sign in with phone / email + code first, then add a Passkey from Security Center.
Effect on 2FA
From 2.2.5, Passkey is also one of the Two-Factor Authentication (2FA) options, listed as Passkey → phone → email → Google. If you already logged in with your Passkey, it is not asked again; if you also turned on phone, email or Google verification, you still complete each one, with no “pick one of three”. See Two-Factor Authentication (2FA) at login. Fund actions such as withdrawals follow different rules; see Verify with Passkey for fund flows.
Newly bound Passkey vs reset Passkey
To prevent account-takeover via a stolen phone, MPChat applies a 24-hour restriction on withdrawals, transfers, and red packets only when you reset a Passkey via face liveness. First-time Passkey binding does not trigger this 24-hour restriction.
Got stuck signing in?
See Passkey troubleshooting for cross-device QR errors, "no Passkey on this device", and other login-flow issues.
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