How to Mail Your Tax Return Online in Canada

Filing your taxes isn’t always as simple as clicking “Submit.”

For many Canadians, NETFILE isn’t an option—whether it’s a first-time return, a special tax situation, or a CRA request for paper documents. In those cases, mailing your tax return becomes mandatory.

The good news? You can mail your tax return online in Canada without printing documents, buying envelopes, or waiting in line at the post office.

This guide walks you through the safest and easiest way to do it using Online-Post.ca.

When Do You Need to Mail Your Tax Return?

You may need to file your return by mail if:

• You’re filing a first-time tax return,
• NETFILE is unavailable for your situation,
• The CRA specifically asks for paper documentation,
• You’re submitting adjustments or special forms.

The CRA confirms that paper returns are still valid and accepted in Canada when properly mailed (see official CRA guidance).

Step 1: Prepare Your Tax Documents Properly

Before mailing your return, accuracy is critical.

Make sure you:

• Save your completed tax return as a PDF
• Include all required attachments (T4 slips, receipts, schedules)
• Sign any required pages (such as the final page of your T1 Condensed)
• Keep a digital copy for your personal records

Most tax software platforms (like Wealthsimple Tax or TurboTax) allow you to download your finalized return directly as a PDF, making this step quick and reliable.

Step 2: Find the Correct CRA Mailing Address

The CRA uses different mailing addresses depending on your province or territory and whether you’re filing a regular return, amended return, or special submission.

Sending your tax return to the wrong address can delay processing. Always confirm the correct address using the official CRA page.

Step 3: Mail Your Tax Return Online with Online-Post.ca

Instead of printing and mailing everything yourself, Online-Post.ca lets you handle the entire process online.

Here’s how it works:

1. Upload your tax return PDF
2. Enter the CRA tax centre address and your return address
3. Choose your mailing option (Regular, Registered, or Express)
4. Pay securely online

That’s it, Online-Post.ca takes care of:

• Professional printing
• Secure enveloping
• Mailing your documents within Canada

You never have to leave home and your return is prepared properly every step of the way.

What Happens After You Mail Your Tax Return?

Understanding what comes next helps avoid unnecessary stress.

Processing Time

According to the CRA, paper tax returns typically take 12 weeks to process.

Proof of Mailing

If timing or confirmation matters, consider using Registered Mail or Express Mail, which offer tracking and delivery confirmation.

Postmark Date Matters

The CRA considers your return on time if it is postmarked by the filing deadline, not when it is delivered. Using a reliable mailing service helps ensure this requirement is met.

Common Questions About Mailing Taxes in Canada

Is it safe to mail my tax return online in Canada?

Yes, it’s safe when done properly. Using our online mailing service reduces many common risks associated with traditional mailing, such as lost documents or late postmarks. Your return is professionally printed, securely prepared, and mailed within Canada following standard postal procedures.

If you’re mailing sensitive documents, choosing a tracked option (Registered Mail or Express Mail) adds an extra layer of confidence.

What’s the best way to send sensitive tax documents to the CRA?

The best approach is to:

• Use a trusted mailing service
• Keep digital copies for your records
• Choose Registered or Express Mail if tracking matters

Online-Post.ca allows you to select the mailing option that fits your needs while handling printing and mailing professionally, so your documents are sent correctly and on time.