If you have a website or a blog and you charge for advertising, links, or reviews, you must report the income on your Canadian income tax returns. Send invoices to your clients and customers. If your invoices exceed $30,000 in the last four consecutive calendar quarters, you must register for HST/GST. Once you are registered, you must charge HST/GST to your Canadian customers and clients. Foreign customers or clients are not charged HST/GST.