If there is insufficient rent in your lockbox to pay the rent when due, the game will check your consignment merchant, if you have one. If there is enough coin on the consignment merchant, the week's rent will be deducted. Very important: coin in your lockbox and coin on your consignment merchant cannot be combined. There needs to be sufficient rent in the lockbox or on the consignment merchant. If there is not sufficient coin to pay the rent, the lot and house will be reposessed.