Hospitals and doctors are notorious for this. The never sent a bill, but think they did and since so many medical bills go into collections their default reaction is right to collections. Almost any other business would try to contact you before going to collections.<p>Unfortunately, the best way to handle it is work for you. First, you need to send a letter to the collection agency demanding proof of the debt. If it is an old debt, odds are they will not want to deal with this and will stop collection attempts. Know the FDCPA [1]. Any legit collection agency should already be following it, but if you start quoting it about time to call, you sent a letter so do not call again, etc... they will take notice.<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fair_Debt_Collection_Practices_Act" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Fair_Debt_Collection_Practices...</a>