Authenticate with mobile number(duplicate mobile number)

Hello guys

I have some issue in user Authenticate System for example there are tow country called X and Y this two country phone code is +9 and +10 (this is only for example) . this two country have two people name called R and M. R person mobile is +9123456789 and M person mobile number is +10123456789.

There are site called P and this two user come to register on that site and enter the mobile number. both people enter the mobile number without country code but this site get user country code via ip address.

But problem is if we save mobile number as what user enter mobile number field will be duplicate. and if save with country code user don't know about it and next time once he came and enter the same mobile number he entered before system will say invalid mobile number.

i would like to know best way bypass this method . most of websites have this issue.

Thanks

--
You received this message because you are subscribed to the Google Groups "Django users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscribe@googlegroups.com.
To post to this group, send email to django-users@googlegroups.com.
Visit this group at https://groups.google.com/group/django-users.
To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/5c0d3b5b-e055-4106-9517-943d3d5594c3%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.