One of the IRS rules is that for it to be a rental property, it has to be placed in service and ready and available to rent. That means that a tenant could move in at a moment's notice. From that time on, you can deduct expenses. Prior to that, improvements must be added to the basis of the property.
From IRS Pub 527: Vacant rental property. If you hold property for rental purposes, you may be able to deduct your ordinary and necessary expenses (including depreciation) for managing, conserving, or maintaining the property while the property is vacant. However, you cannot deduct any loss of rental income for the period the property is vacant.
If you did not place you rental in service yet - (haven't started advertising, still working on remodeling) - please keep records of all your maintenance and repairs. When you do place property into service - add all of these expenses to the cost of your property. The amount will increase your depreciation deduction when the property is available for rent.
If you did place your rental property in service - (the date that your property is ready and available for rent) you can deduct the expenses as usual. When going through the rental information, once general questions about your rental are answered, you will be able to enter rental expenses. For expenses not listed, enter your own description and amount
