I live with my parents in the home they own outright and use a room in the house for my sewing business. I do not pay a formal rent, but I contribute the equivalent of rent to our household each month (about $700.) Can I claim this as a business expense if I do not have a formal lease? The room is used solely for business. Also, are there any forms of proof that would be helpful to claim this? I mainly have domestic bills that I pay via accounts in my name (food, phone, internet, etc.) Thanks so much for any help with this!