Please do not add '8' after Country Code +7
For the phone verification, you should not add '8' after country code +7 (Russia). Yahoo default is automatically adding '8' before my mobile number. Therefore, I will never be able to verify it because Yahoo SMS/Call verification cannot get trough the invalid number.
Please remove the '0'. Thank you.

We’d like to look more into this, please send us a DM on Twitter at @YahooCare, containing your Yahoo ID and a screenshot of your experience.
-
Anonymous commented
Same problem. Correct format of phone number in Russia is +7 111 111 1111
If you choose Russia +7 and inputting phone number 111 111 1111 it is automatically adding 8.
And it looks like +7 8 111 111 1111 and it is not possible to correct.