Atlantic Canada: one return, and a rate your customer decides

The rules turn on the supply and there is not one of them, there are three. For goods, the province is where the goods are legally delivered to the recipient, with deeming rules that fix delivery at the destination named in the carriage contract or at the point possession passes to a carrier the supplier retained on the recipient's behalf. It is not the customer's billing address and it is not where the seller sits. A short lease follows where the property is delivered or made available, while a longer one follows the ordinary location of the property as the parties agreed it. For services the lead rule is different again: the recipient's home or business address in Canada obtained in the ordinary course of the supplier's business, falling to where the Canadian part of the work is performed only where no Canadian address is obtained. That address has to be a real physical location, so an email address or an internet address does not satisfy it. For intangible property the lead test is where the Canadian rights may be used, with the recipient's address entering only as a tiebreak. Three tests, one invoice, and a customer record that either carries the right field or does not.

That is a systems problem before it is a tax problem, which is precisely why it belongs on a finance operations site rather than a tax one. The information the rules need has to be captured when the customer is set up and when the order is taken, not reconstructed at period end out of a shipping report. A customer master holding one address for everything cannot distinguish where a service recipient is located from where goods were delivered, and a billing system with one provincial tax code per customer will charge the same rate on a shipment to a different province as it does on everything else. The failure is quiet and it is the wrong kind of quiet. Undercharging is a liability the company absorbs, because the tax was owed whether or not anybody billed it. Overcharging is a customer problem that surfaces months later when somebody in their accounts payable finally reads a line. Neither is caught by a return that adds up, because a return built out of the billing system adds up either way.

On the employer side the four provinces are not one place, and the difference matters if you are hiring across them. Newfoundland and Labrador levies a payroll tax on employers, calculated on remuneration paid to employees who report for work in the province and administered by the provincial finance department. Nova Scotia, New Brunswick and Prince Edward Island have no employer health tax or payroll levy at all, which is worth knowing precisely because the neighbouring province does. Each of the four has its own workers' compensation authority, separately named and separately administered rather than branches of one body, and registration is not automatic on hiring a person: in Nova Scotia and New Brunswick it turns on whether the industry is covered and on a minimum number of workers, below which coverage is voluntary, while the other two reach further. Corporate income tax across all four is administered federally, so there is no provincial corporate return anywhere in the region.