Although I don't deal much with framework licensing, I'm going to assume it's similar to regular Software licensing - Either with verification of an email showing it's been purchased, or an actual keycode to enter in.
When a client needs software (i.e. Windows Server, or Windows licenses for their personal computers), I do not buy them with my own money. I will give the client a couple choices of where to purchase from, and the exact product name to ask for. Once they buy it, I tell them I can do the work with it then.
By doing this, I am lowering my chances to near zero about getting involved in software licensing, and I do not need to worry about asking for reimbursement for something I don't need, if the client does not pay me for it. Remember, once software has been opened, it's extremely difficult to return it (who's to say it wasn't copied and the key code already used by a previous person?). They purchase the package themselves, then give me the package while I'm on premise to install it.
I have had clients who offered to just write down a keycode, but would always refuse to tell me where they got it from. I can only assume, but not say for certain, that they are hiding it for some reason they don't trust me for. These clients, I just politely say I cannot work with the code, without seeing the actual keycode from its source - a physical package they bought, an email from the company with the payment made, or a reputable website that displays the keycode.
You already know the licensing for that framework, so you need to make sure your client is following the rules. In many jurisdictions (Remember, I am not a lawyer!), other people involved can be on the hook for licensing fees, as well. If it's a small company, you may be able to email them directly, and ask if XYZ Industries has purchased a license for their software. I don't know if you would get a reply, but if they have no record of it, it would send off warning bells... And make me question the client in general.