I got a museum client. They are an A list (whale) client. They eventually always pay, but are constantly overlooking invoices, not paying on time, making mistakes, and it is really starting to bug me. Problem is I can not afford to let them go. I've tried waiting, checking in with them weekly, but its at a point where I don't know what to do?? Are late fees / charges something sign makers do? What about a contract?
In this day and age, there should be contracts. It's not any different then having a string of emails to serve as proof of what was going on.
I've been involved in 2 industries that a lot of people will still go by the "handshake is good enough" and in the majority of instances (unfortunately, at minimum that's only 51% of the time), that's not a problem. It's only when a situation like this happens, that it's a problem.
Everything from assessing late fees, when things get escalated (sent to collections, repo etc) should be spelled out in the contract. Otherwise, how do both parties know when thresholds have been met and what constitutes what? Sometimes, certain things need to be specified in certain ways with certain languages in order to make sure that the contract has you covered. Here (and and at least one other neighboring state) in order to repo something for instance, it has to be specified in the contract and can't use "colorful language" like "emergency repairs" instead of "repossession". That's just a for instance and it can vary from jurisdiction to jurisdiction. Most industries have little minutia like this that's specific to them to take advantage of those protections or have a recourse to fall back on.
Experiences will vary on either side and the outcomes. Some experiences may give a certain false confidence about things. Doesn't necessarily mean the next person will enjoy the same outcome. I just prefer to make sure I'm above board. To me, that goes in with being a professional in whatever I'm doing.
With regard to the whale of a client. In my view, don't really want to have one client that is so crucial to your business. Even if you don't get rid of them, they can get rid of you. Then what happens, up that well known creek without a paddle.