Can I write that off? If you have asked this question, you are in good company. Getting to know what is a true business expense can save you bundles at tax time and prevent CRA to disallow your expenses. It can be pretty hairy, as a tax accountant, to figure out what your expenses should look like if you mixed your groceries bills with office supply receipts. The more you ask your accountant to pull out their calculator, the more it will cost you to get your taxes done. Here is what we recommend to make your life easier (and cheaper).