When you send a GST/HST return, file a refund application or file a notice of objection or appeal, you need evidence for two reasons:
1) To prove that you completed the document; and
2) To prove that you sent the document on or before a statutory deadline or the date requested by the Canada Revenue Agency (CRA).
You may be the unlucky person whose document is lost by Canada Post or the courier during transit or by the CRA after delivery.
First, you should determine if you must use a specific method of transmission of the document. The requirement of a specific method of transmission would be in the applicable provisions of the Excise Tax Act (Canada) and/or applicable regulations. Sometimes there is a specific method of transmission (e.g., by first class mail, by registered mail, etc.) required in the statutory provision and, in these circumstances, you must do as told.
Second, you should make sure you know about any statutory limitation periods (that is, the deadline for filing the document).
Taxpayers are often asked to send documents to the CRA auditor or appeals officer during the course of an audit. There are no rules applicable to the method of sending these documents. Often the CRA give a deadline for sending the documents to the auditor and the auditor may finalize an assessment if the documents requested as not delivered on time.
In all cases where you must send documents to the CRA, you should pick a method that gives you proof of transmission. For example, when you send a document by registered mail, you can ask for a "return receipt", which is a document from Canada Post showing proof of delivery by Canada Post to the CRA. Also, you will have also received a document showing proof of delivery to Canada Post of the envelop to be sent by registered mail and both the envelop and the receipt are date stamped. This is really good proof that you delivered the document to be sent on a particular day.
I have experienced situations where Canada Post's rules cause a document that I wish to send to the CRA to be rejected (e.g., envelop is too big or that the document weighs too much). In these cases, if the Excise Tax Act or regulations requires that I send the document by registered mail, I send a letter and partial document by registered mail and send the entire document by courier. I note in the letter to be sent by registered mail that I have attempted to follow the requirement to send the document by registered mail as required by the statute and that Canada Post has rejected the document. I indicate the letter is being sent in accordance with the requirement and that I am sending the complete document by courier. I give the courier tracking number in the letter. This demonstrates that the courier package was sent prior to the letter, which was sent within the rules. I maintain evidence of both documents that I have sent on or before the statutory deadline.
The recent case of Liao v. The Queen is a good example as to why evidence is important. In this case, a taxpayer sent a GST refund application by regular mail. When the taxpayer followed up with the CRA, the taxpayer learned that they had not received the refund application and the taxpayer sent another copy of the refund application. The second copy was sent after the limitation period had expired and the CRA rejected the application as out-of-time. The Tax Court of Canada accepted that the taxpayer had sent the first copy and that first copy was sent within the statutory limitation period. The taxpayer was lucky that the Tax Court of Canada accepted the testimony. The relevant deeming provisions in the Excise Tax Act indicate that anything sent by first class mail is deemed to have been received by the CRA on the day it was mailed. Ordinary mail is considered to be first class mail. A deeming rule causes something to be accepted as a true fact even if it may not be accurate.
In the end, evidence is key. Liao would have been in a stronger position if it could be proved that the refund was sent on the first occasion. Likely, the CRA would have accepted that the refund application was lost and the case would not have made it to the Tax Court of Canada. Liao would have been saved from the stress and the cost of an appeal if it had verifiable evidence of the first transmission within the limitation period.
The last tip that I would like to give you is that you should scan your proof on transmission because it is easier to find it in your computer records when needed. Also keep the originals in a safe place. I like to use purple coloured file folders for all important documents in a file.