diff --git a/app/main/forms.py b/app/main/forms.py
index 33e4d1c0c..dc2b18e33 100644
--- a/app/main/forms.py
+++ b/app/main/forms.py
@@ -37,19 +37,10 @@ class UKMobileNumber(TelField):
 
     def pre_validate(self, form):
         try:
-            self.data = validate_phone_number(self.data)
+            validate_phone_number(self.data)
         except InvalidPhoneError as e:
             raise ValidationError(e.message)
 
-    def post_validate(self, form, validation_stopped):
-
-        if len(self.data) != 9:
-            return
-        # TODO implement in the render field method.
-        # API's require no spaces in the number
-        # self.data = '+44 7{} {} {}'.format(*re.findall('...', self.data))
-        self.data = format_phone_number(self.data)
-
 
 def mobile_number():
     return UKMobileNumber('Mobile phone number',
diff --git a/tests/app/main/test_phone_number_form_field.py b/tests/app/main/test_phone_number_form_field.py
deleted file mode 100644
index 086e4bff0..000000000
--- a/tests/app/main/test_phone_number_form_field.py
+++ /dev/null
@@ -1,75 +0,0 @@
-import pytest
-from wtforms import Form
-from app.main.forms import UKMobileNumber
-
-
-class FormExample(Form):
-    phone_number = UKMobileNumber()
-
-invalid_phone_numbers = sum([
-    [
-        (phone_number, error) for phone_number in group
-    ] for error, group in [
-        ('Too many digits', (
-            '0712345678910',
-            '0044712345678910',
-            '0044712345678910',
-            '+44 (0)7123 456 789 10',
-        )),
-        ('Not enough digits', (
-            '0712345678',
-            '004471234567',
-            '00447123456',
-            '+44 (0)7123 456 78',
-        )),
-        ('Must be a UK mobile number (eg 07700 900460)', (
-            '08081 570364',
-            '+44 8081 570364',
-            '0117 496 0860',
-            '+44 117 496 0860',
-            '020 7946 0991',
-            '+44 20 7946 0991',
-            '71234567890',
-        )),
-        ('Must not contain letters or symbols', (
-            '07890x32109',
-            '07123 456789...',
-            '07123 ☟☜⬇⬆☞☝',
-            '07123☟☜⬇⬆☞☝',
-            '07";DROP TABLE;"',
-            '+44 07ab cde fgh',
-        ))
-    ]
-], [])
-
-valid_phone_numbers = [
-    '07123456789',
-    '07123 456789',
-    '07123-456-789',
-    '00447123456789',
-    '00 44 7123456789',
-    '+447123456789',
-    '+44 7123 456 789',
-    '+44 (0)7123 456 789'
-]
-
-
-@pytest.mark.parametrize("phone_number", valid_phone_numbers)
-def test_phone_number_accepts_valid_values(phone_number):
-    form = FormExample(phone_number=phone_number)
-    form.validate()
-    assert form.errors == {}
-
-
-@pytest.mark.parametrize("phone_number, error_message", invalid_phone_numbers)
-def test_phone_number_rejects_invalid_values(phone_number, error_message):
-    form = FormExample(phone_number=phone_number)
-    form.validate()
-    assert form.phone_number.errors[0] == error_message
-
-
-@pytest.mark.parametrize("phone_number", valid_phone_numbers)
-def test_phone_number_outputs_in_correct_format(phone_number):
-    form = FormExample(phone_number=phone_number)
-    form.validate()
-    assert form.phone_number.data == '+447123456789'
diff --git a/tests/app/main/test_phone_validation.py b/tests/app/main/test_phone_validation.py
deleted file mode 100644
index 62595d5da..000000000
--- a/tests/app/main/test_phone_validation.py
+++ /dev/null
@@ -1,68 +0,0 @@
-from app.utils import (
-    validate_phone_number,
-    InvalidPhoneError
-)
-
-import pytest
-
-valid_phone_numbers = [
-    '07123456789',
-    '07123 456789',
-    '07123-456-789',
-    '00447123456789',
-    '00 44 7123456789',
-    '+447123456789',
-    '+44 7123 456 789',
-    '+44 (0)7123 456 789'
-]
-
-invalid_phone_numbers = sum([
-    [
-        (phone_number, error) for phone_number in group
-    ] for error, group in [
-        ('Too many digits', (
-            '0712345678910',
-            '0044712345678910',
-            '0044712345678910',
-            '+44 (0)7123 456 789 10',
-        )),
-        ('Not enough digits', (
-            '0712345678',
-            '004471234567',
-            '00447123456',
-            '+44 (0)7123 456 78',
-        )),
-        ('Must be a UK mobile number (eg 07700 900460)', (
-            '08081 570364',
-            '+44 8081 570364',
-            '0117 496 0860',
-            '+44 117 496 0860',
-            '020 7946 0991',
-            '+44 20 7946 0991',
-            '71234567890',
-        )),
-        ('Must not contain letters or symbols', (
-            '07890x32109',
-            '07123 456789...',
-            '07123 ☟☜⬇⬆☞☝',
-            '07123☟☜⬇⬆☞☝',
-            '07";DROP TABLE;"',
-            '+44 07ab cde fgh',
-        ))
-    ]
-], [])
-
-
-@pytest.mark.parametrize("phone_number", valid_phone_numbers)
-def test_phone_number_accepts_valid_values(phone_number):
-    try:
-        validate_phone_number(phone_number)
-    except InvalidPhoneError:
-        pytest.fail('Unexpected InvalidPhoneError')
-
-
-@pytest.mark.parametrize("phone_number, error_message", invalid_phone_numbers)
-def test_phone_number_rejects_invalid_values(phone_number, error_message):
-    with pytest.raises(InvalidPhoneError) as e:
-        validate_phone_number(phone_number)
-    assert error_message == str(e.value)