The guide on the CRA website says that this is for calculating telephone and utility expenses according to the business-use-of-home rules. Which makes a lot of sense for fixed services, my home phone etc. But what about cell phones? I don't actually have a home phone line and use my cell phone as my only phone. So it's used for a mix of business and personal use that's hard to quantify. Can Canadian self employed individuals claim a part of their cell phone if it's mixed use? Or are cell phones only claimable if they're business phones? (In which case that'd be simple... 100% claimed)