Registration Fields For Uploads

Hi everyone,
I am running a website for The Complementary Therapy Association Of Ireland (https://www.therapy-ireland.com) and I need my prospective members to upload copies of their certificates / diploma’s during the registration process.
My question is this – is there any way I can easily add a new registration field that allows them to upload pdf’s or image files as part of their registration process, or else, after registration, once they choose a membership package from their My Account page?
Any suggestions would be very gratefully accepted!
Best Regards,
Paul