For safety always have a contract that also states who the copyright owner is. In New Zealand's copyright act there's a terrible bit of law called a "commissio

For safety always have a contract that also states who the copyright owner is. In New Zealand's copyright act there's a terrible bit of law called a "commissioning clause" that says if person A commissions person B to produce some work and there's some assumption about A paying B, then A owns all the rights to it even if they neither paid for it nor explicitly agreed to pay. There was a case of a company producing a free sample of engineering work and then trying to reuse that elsewhere. The court decided the recipient of the work was the copyright owner and the company that produced it could not reuse it. Where was the payment? They hoped the recipient would layer become a paying client for future work. Most other developed countries have removed similar clauses but NZ's government recently voted to retain theirs. IAAL