Download a letter of intent to sue (with settlement demand) to inform a defendant that you will sue if they don't pay a settlement amount. A letter of intent to sue (with settlement demand) notifies an individual that the sender intends to file a lawsuit against them.This article explains what demand letters are, when they are useful, and how to write them. Consider the "who, what, where, and when" of your dispute. Learn how to write a personal injury demand letter for a car accident settlement in Texas. And the tips in this article actually work. A settlement demand letter is designed to make the strongest case possible for why you deserve appropriate financial recovery. The letter should make it clear that you are preparing to take legal action against them if your demands aren't met or at least reasonably considered.