How to change telephone number to not being required on the admin side billing and shipping information?
Could this be done with some SQL query?
Here's the SQL query for setting the attribute telephone
to not required.
UPDATE eav_attribute SET is_required = 0 WHERE attribute_code = 'telephone';
You might want this implemented in a setup script if you wish to package it in an extension.
This does not override any frontend code, which may still require the telephone.
app/code/core/Mage/Customer/Model/Address/Abstract.php
comment out getTelephone()
check.
app/code/core/Mage/Customer/Model/Address/Abstract.php
it returns error "insert phone number". I don't try it with default checkout, but i think it returns error anyway because it checks phone number as required.