The Canada Revenue Agency (CRA) now has a service called Business Registration Online which allows business owners to register for a Business Number, GST / HST account, or other accounts (i.e. payroll).
The GST / HST registration online is fairly simple, however you do have the option of calling the CRA at 1-800-959-5525 to register has well.
Once you have registered for GST / HST, you will be able to collect the applicable taxes for all of your sales transactions, and claim input tax credits (ITCs) for all applicable business purchases.
The net amount of GST / HST collected less the ITCs claimed will be the amount that you will need to remit to the CRA.
Note: once you have registered for GST / HST you will need to show your GST / HST account number on all of your invoices going forward.
If you have any questions on GST / HST or need help preparing your return, please contact us.