04/01/2026
Ahoy! Tax season reminder for solo plumbers in Ontario:
Your CRA deadline for self-employed is June 15, but any balance owing is due April 30. If you owe and pay late, you're getting charged interest from May 1 regardless of the June deadline.
A few things most solo operators forget:
Your vehicle log matters. CRA can deny your entire vehicle claim if you don't have a logbook. KMs to job sites, supply runs, dump runs. all deductible, but only if you tracked it.
Tools and equipment under $500 can be fully expensed in the year you bought them. Over $500 goes into CCA (capital cost allowance) and gets written off over time. Keep every receipt.
Home office deduction, if you do your quotes and invoicing from home, you can claim a percentage of rent/mortgage interest, utilities, and internet based on square footage used.
Materials you bought and didn't bill back to the client are deductible. But if you can't prove what job they went to, it gets messy. This is where most guys lose money -- they buy parts, don't document which job it was for, and their accountant can't match it up.
Phone bill is partially deductible. So is your insurance, licensing fees, WSIB, union dues, and any software you use for the business.
The biggest write-off most plumbers miss: unbilled work. If you did the job and never invoiced it, you lost the money AND you can't claim the expenses cleanly.
Speaking of which, this is exactly why I built JobDocket. You talk into your phone for 60 seconds after a job and it writes the record for you. Client, site, hours, materials, all documented. Come tax time, you actually have records instead of a shoebox full of receipts and no idea which job they belong to. jobdocket.ca 3 free, $9.99/mo after that. Built here in Waterloo.
Good luck out there this tax season.