In Canada, the GST is a federal sales tax. Depending upon which province you are selling in, the GST can be applied before, after, or at the same time as the PST provincial sales tax. Both taxes must be listed separately on the receipt, and while the GST must be applied to all sales, PST might not be applied for services (as an example). For POS systems, this generally means that a system must be GST certified in order to be used by a Canadian retailer. BTW, thanks to Heidi Stieh for setting me straight on this one.