This is generally negotiable between home owner and house sitter. As a general rule however, those bills that are paid annually such as rates or council tax should remain with the home owner, while all ongoing costs such as gas, electricity, phone, internet access and water could be paid by the house sitter. It's a good idea to take meter readings of all the utilities on the day that the house sitter moves in so that their exact liability can be worked out upon the home owner's return. All of the costs incurred by the house sitter while looking after resident pets and maintaining the property should be met by the home owner. If the sitting assignment is for an extended period such as a year, the house sitter could agree to meet all of the bills. Be particularly careful about negotiating the paying of bills for a house sitting assignment in a cold winter or a very hot summer. In these cases it is wise to establish approximate heating (or cooling) costs and sign off on these before the assignment begins.