You might be tempted to buy a property to rent now that property values are coming back down to Earth, particularly in previously red-hot southern markets.

Perhaps you already own a rental property. Here are the common rental expenses you can claim: interest on the mortgage, repairs to the property from the tenant's wear and tear, management fees paid to a property manager, condo fees, utilities, property taxes, accounting fees, landscaping, insurance, advertising and office expenses such as bank charges and long-distance calls to tenants.

Less common deductible costs include interest cost on a line of credit for a down payment on the rental property and legal fees paid to draw up a lease agreement.

Here is what you cannot deduct as a rental expense: legal fees paid to purchase the property. This cost is added to the cost of the property, which reduces your capital gains (or increases your capital loss) when you sell. The same applies to travel costs to, say, Vancouver, to shop for a rental property; these acquisition costs are added to the cost of the property.

What about other travel costs related to the rental property? Here's a common scenario. You live in the North, own a rental property in, say, Edmonton and check on the property whenever you travel south for vacation. Can you claim a portion of your travel costs? The Canada Revenue Agency tries to explain deductible travel expenses in their Rental Guide.

Travel expenses, according to the CRA, are limited to transportation costs and do not include board and lodging. Travel expenses are deductible if they are incurred to collect rent, supervise repairs and manage your properties if certain criteria are met. These depend on whether you own just one or more than one rental property and whether the property or properties are located where you live or elsewhere. The CRA's criteria fill the page but fail to provide clear information.

A Tax Court of Canada case, Venditti versus The Queen, Sept. 30, 2008, provides some help. Here's the gist of it. An Ontario taxpayer owned a rental condo in Florida. In 2001, she drove twice to her condo to inspect the property, meet with the condo association and to paint the condo. In 2002, she again drove twice to her condo to inspect the property and meet with the property manager. She explained that the trips - the total duration was more than two weeks each year - had no personal component and everything to do with the condo.

The CRA denied the vehicle expenses because the property was already managed by a property manager, the repairs done by the taxpayer weren't necessary and she did not transport tools and material in her vehicle.

The judge, without explaining why, accepted the taxpayer's explanation and allowed the travel costs originally claimed.

Which must leave you to wonder - when can one claim travel costs against rental income? As a rule of thumb, you should claim necessary travel costs such as when you have to be present to supervise contractors or to authorize repairs, particularly after you booted out a difficult tenant. As for claiming travel costs to check on your property annually, that's questionable at best, unless you have a valid reason for having to be there.