NETFILE not working: CRA-side causes and fixes

Quick checks when NETFILE is not working

Before reinstalling anything, work through these checks. They take a few minutes and rule out the causes the CRA itself documents: service hours, season dates, eligibility and identity details.

This page deals with the CRA side. If your software crashes, will not update or shows its own internal error number, the fix is in the software's help pages. If the CRA received your data and sent back a refusal, go to NETFILE rejected instead, because a refusal needs a different fix from a failed connection.

Is NETFILE down? Maintenance and season dates

The CRA takes NETFILE offline every day from 3 a.m. to 6 a.m. Eastern time for maintenance. That window is midnight to 3 a.m. in British Columbia, so late-night filers on the West Coast run into it more often than anyone else. Wait until after 6 a.m. Eastern and try again.

The service also closes for several weeks each winter. The current season ends on Friday, January 29, 2027, and in 2026 the service stayed closed from February 1 until 6:00 a.m. Eastern on February 23. The 2027 reopening date is not yet announced; our NETFILE open date page tracks it.

NETFILE not working in 2026 for a 2026 return

A common mix-up in the fall is trying to send a return for the year that has not ended. NETFILE currently accepts tax years 2018 to 2025 only. A 2026 return cannot be sent until the 2027 season opens, however complete it is.

What are the NETFILE hours of service?

NETFILE is open seven days a week during the season. The only daily gap is the CRA's maintenance window, 3 a.m. to 6 a.m. Eastern time, which falls at a different local hour across the country. H&R Block's help page lists the same window for Auto-fill My Return and My Account, so a slip download that fails at that hour has the same cause.

If your software shows the message "NETFILE is not operational at this time", the service is closed; your return has not been refused. Tax software help pages tie that message to CRA maintenance. Wait until the window above ends and try again, or, if you are trying after the season closes on January 29, 2027, wait for the 2027 opening date.

Your return is not eligible for NETFILE

Some returns can never be sent through NETFILE, and good software will warn you before you try. The CRA excludes returns for a person who died, bankruptcy returns, returns for years outside the accepted range and returns for deemed residents.

Less obvious exclusions catch people with unusual situations: income from Lloyd's of London, employment with a prescribed international organization, pension income that accrued before 1972, foreign tax credits for more than 3 countries, more than 12 sets of financial statements, SR&ED expense deductions, and claims involving more than 22 children. The full list is on our NETFILE eligibility rules page.

SIN and filing limits

NETFILE needs a social insurance number starting with 1 to 9, or a temporary tax number starting with 01 or 03. A SIN starting with 0 is accepted only for a newcomer to Canada. If you are registered for Represent a Client to file for others, the limit is 20 returns per computer or CRA account for each tax year.

Identity details do not match CRA records

If the connection works but the CRA will not accept the return, the likeliest cause is a mismatch. The CRA compares your name, date of birth and SIN with its own file. A different spelling, a missing hyphen, a recent surname change or a transposed birth date is enough to stop it.

• Compare your name with how it appears on your last notice of assessment, not how you usually write it.
• Check the date of birth format your software uses: day and month swapped is a frequent slip.
• If you changed your name, make sure the software records the change rather than just the new name.
• If you entered an access code, confirm it came from your most recent notice of assessment, or clear the field.

If your details are right and the CRA's records are wrong, for example an incorrect birth date on file, the CRA's Electronic Filers Manual (RC4018) says the taxpayer will need to provide original or certified documents to resolve the discrepancy. Until then, a paper return is the practical way to file.

Other ways to file if NETFILE will not work

Do not let a technical problem make you late. If you owe tax, the late-filing penalty is 5% of the balance owing plus 1% of that balance for each full month late, up to 12 months.

1. Try again after the daily maintenance window or at a quieter time of day.
2. If the return type is excluded or your records do not match, print the return and mail it. Our paper tax return page explains where to send it and how long processing takes.
3. If you have a representative or preparer, they can send an eligible return through EFILE.
4. Keep proof of when you mailed or sent the return, in case the timing is questioned later.

The CRA also charges interest on overdue tax at its prescribed rate, which is 7% for October to December 2026, the same as for July to September, separately from the penalty. Pay what you owe by April 30 even if the return itself goes by mail. More on how the service is meant to work is in our NETFILE Canada guide.