/v1/otps/sms/login_or_create endpoint is giving error sending OTP

Getting error while calling the /v1/otps/sms/login_or_create

    "status_code": 400,
    "request_id": "request-id-test-44968c3a-d163-4db8-bbec-aca4d7fa50d9",
    "error_type": "invalid_phone_number",
    "error_message": "Phone number format is invalid. Ensure the phone number is in the E.164 format.",
    "error_url": "https://stytch.com/docs/api/errors/400#invalid_phone_number"

the request body that I am sending:

    "phone_number": "+91<my_phone_number>"

I am able to use this API with my test account credentials for other mobile numbers. It’s just my number that throws this error. I was able to use my number till Friday 6/09/2023

I can DM my mobile number if that helps investigating.

Hey Romil – thanks for posting!

It looks like we’ve started receiving the following error from our messaging provider when attempting to send SMS to your phone number: https://www.twilio.com/docs/api/errors/21610

Could you please try texting START to +14153225608 to see if that resolves the issue?

Hi nicole, thanks for the quick response.
I sent “START” to +14153225608. But the API still gives the same response. Let me know if there’s something else that I can try?

Hey Romil,

Got it, thanks for trying that! Sorry about the continued issues here.

For troubleshooting purposes, would you mind trying again but sending the word “UNSTOP” instead this time (to the same number)? Can you also confirm whether you receive an automated resopnse back when sending “UNSTOP”? Thanks!

Hey Matt,
I did send UNSTOP. I also received an automated response back.
Response says, “You’ve successfully been re-subscribed to messages from this number”

the problem persists. error is the same

Hey Romil,

Got it - thank you so much for giving that a shot and letting us know! We’ve escalated this issue with our messaging provider and will follow up here with any updates.

In the meantime, you should be able to test the OTP flow out with a different phone number, or with the same phone number using our WhatsApp OTP product. The /authenticate call is the same for a WhatsApp based flow, so the only thing you’d need to adjust is the /send or /login_or_create call.

Hey Romil,

Thanks for your patience here - we’ve made some changes on our end that should resolve the underlying issue. For context, phone numbers with similar prefixes were being partially blocked by our messaging provider due to some prior suspected fraudulent activity (unrelated to your requests), which we’ve worked with the provider to resolve.

Would you mind re-sending an SMS OTP to the affected phone number, and letting us know if you run into any further issues? Thanks so much!

Hey Matt,
I was able to receive an OTP via SMS successfully. Thanks for all the help

Hey Romil,

Awesome, thanks so much for confirming! Let us know if there is anything else we can help with!