I am a sole proprietor and file two T2125's annually. Each of these represents a business activity that is separately identifiable mainly by nature of activities (different industry codes) and I keep separate records for each. They both operate at the same location under my personal legal name.

I was originally advised that if I have multiple types of business activity as a sole proprietor (e.g. one which offers a marketing service, and another which manufactures and sells machine parts), each would need to be reported on a separate T2125, even if both are operating under my own name at the same location.

In order for me to begin charging HST, would I need to complete a GST10 to apply for separate HST sub accounts to use for each T2125/business activity (e.g. RT 0001 and RT 0002) and file two different GST/HST returns?

If not, would I use the same HST account number on both T2125's, and simply combine the numbers and file a single GST/HST return?