With regards to mortgage ... you can only right off the PORTION of the INTEREST on your mortgage and the PORTION of your Property tax using the equation given by the CRA for us .... so how many square feet of your home you use for business over the total square footage of your home by how many hours a day you are open over 24 hours over how many days you are open over 365 days in a year....and be careful with the Turbo Tax - because their 'program' does not do the equation properly for HOME CHILDCARE which is a unquie business - the equation used in that program is done assuming that the space used for business is NEVER used for personal use as well ... so unless you have a 'dedicated' daycare space with a kitchen, bathroom and playroom where the kids sleep that is NEVER used by family you have to TRICK that program into doing the PROPER % by figuring our your % manually and than putting in a square foot ration that equals that .... otherwise you will write off way more than you are 'entitled' to and in an audit you will end up having to repay any taxes as a result

Unfortunately we cannot write off the principle because in our case WE own our home the DAYCARE BUSINESS does ... if you DID put the principle in your home down as a business expense when you SOLD your house you would have to claim any PROFIT you make on it as income and pay tax on that - and well ouch when that time comes