What if the client cross-complains that my work was defective?

This happens fairly often in practice, and it's typically the main reason a case that started out looking like a simple unpaid-invoice matter stops being simple at all. Once the client is genuinely disputing liability itself, arguing your work wasn't done properly rather than just failing to pay for work they agree was done, you've moved into a real, contested piece of litigation involving discovery and formal motions, not a straightforward collection of an admitted debt.

That shift matters practically because it changes what kind of assistance actually fits your situation. Document preparation and filing help is generally scoped for straightforward collection matters, while a genuinely contested defective-work dispute usually calls for representation carrying the case through the more involved litigation process that follows.