If you both have a secondary occupation (sole proprietor) but you are going to carry out this job (e.g. painting) with two people.
Example: it is a project worth €10,000 excl. VAT (quoted price), the necessary materials cost €3,000 excl. VAT. This leaves €7,000 gross.
Can one person invoice the other for their share, in this case €3,500, without charging vAT?