In Canada, various provincial and federal taxes are applied to goods and services. In the event that a tax rate changes, there can often be confusion as to which tax rate to use for services rendered. For example these events may not occur on the same day and may have different tax rates:
- date when the service was requested
- date when the service was completed
- date when the service was invoiced
- date when the service was paid
... and one can make a case for any of them as the date to calculate the taxes.
Most of our business is in Ontario, but we deal across the country. The provinces have their own rules. For example, Manitoba has had a change recently. Rather than try to encode various rules based on dates, addresses, and everything else, and try to keep them up-to-date, we're going to default to Ontario rules, still keep the individual provincial rates, etc., but when a change to a taxation rate occurs, use the Ontario rules to calculate, and deal with any ± discrepancies on a case-by-case basis as one-time manual tax adjustments.
Does anyone know a reference, on-line or otherwise, to define which date should be used to determine the tax rate to apply for taxable services for Ontario, Canada?