File Size Limitation on Custom Field = File Upload

My site depends on the ability for a user to upload a file during the checkout process. I see how to do that using the Custom Field with field type=file. When I select this option, the user is limited 2MB. There is even help text that explains:
maximum upload file size : 2M *

Is this maximum upload file size configurable? Is this set somewhere else in Joomla or in Hikashop? The files I need to collect will frequently be larger than this and up to 5MB. Thanks for any assistance you can offer.

I checked my server and the php.ini file in my root contains:
upload_max_filesize = 64M;

Could this setting be somewhere else?