If you are short on cash, you might say you have a financial problem. Talking about finances is a polite and formal way to refer to money.
The similarity between the words financial and finish is no accident. Both come from the Old French word fine, which was generally used to mean "end" or "finish" and more specifically to mean "end a debt." If you pay a fine, you end the debt you owe society for, say, spitting your gum on the sidewalk, or failing to clean up after your dog.