Repo-man

The repo-man is an NPC that visits a Sim's residential lot when their bills have been unpaid for too long. Over time, after bills have been delivered to a house, they change color, going from white, to yellow, to orange to red. As they progress through the colors the need to pay them becomes more urgent. It's (approximately) two days between color changes. Once bills stay red for more than two days, they will warn the player at 7:00am that they must be paid immediately. The player has until 6:00pm the next night to pay, otherwise the red bills will explode and summon the repo-man.

He usually takes one or two items, but if the Sim is in a large amount of debt he may take several. The item/items he takes (approximately) add up to the amount the Sim owes. The Sims of the household get a negative memory for each of the items taken, and may periodically cry about the lost item(s).

In most of The Sims games, he wears dark attire. He will come onto the lot and use a gun-like device on whatever he is going to repossess. The gun's special effects may vary from game to game, but the result is that the item vanishes.

The repo-man in The Urbz: Sims in the City is Harry Snivel, who is also the landlord and also one of the three main villains.

If forced to come in The Sims 3 with testingcheatsenabled, the repo-man will take a large amount of items (sometimes at least twenty items) regardless of whether any debt is owed.

In The Sims 2 and The Sims 3, if the player removes the doors leading into their house, the repo-man will use his teleporter to gain entrance. In The Sims, he will simply use his gun outside, and the object will still be repossessed.

In The Sims 2, if the household does not have any objects that can be taken, the repo-man will criticize the family for wasting his time, then leave. If Nightlife or later is installed, the player can simply place all items in the inventory before he arrives, and then replace them when he's gone. In The Sims 3, the repo-man will subtract household funds that are approximately of the same value as the amount owed.

Desiderata Valley Repo Men
In The Sims 3, if the player's Sims live in a house built on an ancient burial ground, the repo-man will suck up the graves with his gun. He will then warn the Sim to pay their bills or he will be back.

In The Sims 2 and The Sims 3, the repo-man can be removed with testingcheatsenabled by shift clicking, force error, and then Delete. This will not cause any corruption or issues, other than kicking the repo-man off the lot. However, the truck will need to be deleted manually, or, if in Isla Paradiso, the repo-man's boat.

Trivia

 * If he is present in The Sims 3 and if you try to save the game while he's present, the game will ask if you want to save in the current situation.
 * In The Sims, due to the ability to create a family that only contains children, the repo-man will take your objects due to not paying the bills (since only adults can pay bills). This can be prevented by using the move_objects on cheat and delete the mail woman before she could put the bills into the mailbox. The Sims 2 and The Sims Stories fixed this by requiring at least one adult in the playing household.
 * One commonly experienced problem in The Sims 3 is that when a player changes their active household but then returns to the original lot after a few days, a repo-man may appear after a few Sim-hours as the Sims did not pay the bills in the player's absence.
 * In The Sims 2, the repo-man has an incomplete character file, and should therefore not be interacted with outside his designated in-game purpose. Doing so can cause game corruption, fixed only by uninstalling and reinstalling the game.
 * In the Sims 2, if he is made playable, he will have no voice and his PlumbBob will be inside his body, rather than above his head.
 * Locking the doors or using the "alwaysallowbuildbuy" cheat and building walls around the repo-man will not stop him.
 * If you delete the repo-man using cheats, he will come out of the truck a few seconds later. It will usually be a different repo-man.
 * The repo-man has a way to foil almost every trap or cheat imaginable. Nothing stops him except paying the bills, using cheats and deleting the mail woman before the bills are placed in the mailbox, or by deleting the repo-man's truck.
 * The repo-man does not appear in The Sims 4. Instead, delinquency in paying bills results in utilities being shut off.
 * In The Sims 3, slightly scary music will indicate his presence.