What's the best way to store a phone number in Django models?

I am storing a phone number in model like this:

phone_number = models.CharField(max_length=12)

The user would enter a phone number and I would use the phone number for SMS authentication. This application would be used globally. So I would also need a country code. Is CharField a good way to store a phone number? And, how do I validate the phone number?

You might actually look into the internationally standardized format E.164, recommended by Twilio for example (who have a service and an API for sending SMS or phone-calls via REST requests).

This is likely to be the most universal way to store phone numbers, in particular if you have international numbers work with.

1. Phone by PhoneNumberField

   You can use the phonenumber_field library. It is a port of Google's libphonenumber library, which powers Android's phone number handling. See django-phonenumber-field.

   In the model:

   from phonenumber_field.modelfields import PhoneNumberField
   
   class Client(models.Model, Importable):
       phone = PhoneNumberField(null=False, blank=False, unique=True)
   

   In the form:

   from phonenumber_field.formfields import PhoneNumberField
   class ClientForm(forms.Form):
       phone = PhoneNumberField()
   

   Get the phone as a string from an object field:

   client.phone.as_e164
   

   Normalize the phone string (for tests and other staff):

   from phonenumber_field.phonenumber import PhoneNumber
   phone = PhoneNumber.from_string(phone_number=raw_phone, region='RU').as_e164
   

2. Phone by regexp

   One note for your model: E.164 numbers have a maximum character length of 15.

   To validate, you can employ some combination of formatting and then attempting to contact the number immediately to verify.

   I believe I used something like the following in my django project:

    class ReceiverForm(forms.ModelForm):
        phone_number = forms.RegexField(regex=r'^\+?1?\d{9,15}$',
                                        error_message = ("Phone number must be entered in the format: '+999999999'. Up to 15 digits is allowed."))
   

---

As per jpotter6, you can do something like the following in your models as well:

File models.py:

from django.core.validators import RegexValidator

class PhoneModel(models.Model):
    ...
    phone_regex = RegexValidator(regex=r'^\+?1?\d{9,15}$', message="Phone number must be entered in the format: '+999999999'. Up to 15 digits allowed.")
    phone_number = models.CharField(validators=[phone_regex], max_length=17, blank=True) # Validators should be a list

Use django-phonenumber-field:

pip install django-phonenumber-field

Use a CharField for the phone field in the model and the localflavor app for form validation:

https://docs.djangoproject.com/en/1.7/topics/localflavor/

As of 2021-12-07, it looks like LocalFlavor is no longer part of Django.

This solution worked for me:

First install django-phone-field. Command:

pip install django-phone-field

Then in file models.py:

from phone_field import PhoneField
...

class Client(models.Model):
    ...
    phone_number = PhoneField(blank=True, help_text='Contact phone number')

And in file settings.py:

INSTALLED_APPS = [...,
                  'phone_field'
]

It looks like this in the end:

Validation is easy. Text them a little code to type in.

A CharField is a great way to store it. I wouldn't worry too much about canonicalizing phone numbers.

It all depends on what you understand as a phone number. Phone numbers are country-specific. The localflavors packages for several countries contains their own "phone number field". So if you are OK being country-specific you should take a look at localflavor package (class us.models.PhoneNumberField for the US case, etc.)

Otherwise you could inspect the localflavors to get the maximum length for all countries. Localflavor also has forms fields you could use in conjunction with the country code to validate the phone number.

I will describe what I use:

Validation: The string contains more than 5 digits.

Cleaning: removing all non-digit symbols and writing only numbers to the database. I'm lucky, because in my country (Russia) everybody has phone numbers with 10 digits. So I store only 10 digits in the database. If you are writing a multi-country application, then you should make a comprehensive validation.

Rendering: I write a custom template tag to render nicely it in the template. Or even render it like a picture - it is safer to prevent SMS spam.

Others mentioned django-phonenumber-field. To get the display format how you want you need to set PHONENUMBER_DEFAULT_FORMAT setting to "E164", "INTERNATIONAL", "NATIONAL", or "RFC3966", however you want it displayed. See the GitHub source.

First of all, you need to install the phone number Django package.

pip install django-phonenumber-field[phonenumbers]

Then next is to add it to the installed applications:

INSTALLED_APPS = [
    ...
    'phonenumber_field',
    ...
]

This is how to use it in your model:

from phonenumber_field.modelfields import PhoneNumberField

class Artist(models.Model):

    phone_number = PhoneNumberField()