I've had a debt go to collections one time. It was a medical bill that I had somehow lost track of (or maybe never received). It was legit but I had never seen it. I will say that the collection company was very cordial and almost apologetic, I told them I would need to confirm the debt since it was a complete surprise, which I did, and I paid the provider (not the collector) directly. Never heard from them again, and it never affected my credit score.