What deductions do I get with a nanny?

Hi all,

In the past my nanny has acted as an independant contractor - she did her own taxes and we just paid her a flat rate.

In the new year I will have a new nanny who wants me to pay her taxes for her. I just went online and applied for a Business Number so that I can deduct her payroll taxes.

I want to know what expenses I can deduct. I will be providing her with breakfast and lunch, providing her with a Metropass every month, and we will be using my own house as the "daycare facility".

Can I deduct a proportion of heat, electricity, water, mortgage, property tax, and other household bills for running the business in my home? What about a proportion of my grocery bill? And the Metropass?

If anyone has any experience with this, I would love some help. I know that there are services that will figure this all out for a fee, but I would prefer to do it myself.

Thanks!