Construction accounting isn’t like running a shop or a café. Holdbacks, progress billing, subcontractors, and GST/HST timing all create traps that can hurt your cash flow or land you in trouble with the CRA. Here’s how to keep the books clean on a trades or construction business in 2026.
Construction accounting is trickier because of holdbacks (money withheld until a job’s done), progress billing across long projects, and lots of subcontractors. Key rules to nail: track holdbacks separately (they’re generally taxable when invoiced/receivable, and GST/HST timing follows specific rules), file a T5018 slip for payments to subcontractors, and be careful classifying workers as employees vs subcontractors (the CRA scrutinizes this). Get job costing right and you’ll actually know which jobs make money.
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Why Construction Accounting Is Different
Unlike a business that sells and collects right away, construction involves long jobs, staged payments, retained funds, and a web of subs and suppliers. Revenue and costs don’t line up neatly in one month, so you need systems for:
- Recognizing revenue over a project (not just when paid)
- Tracking costs by job, not just by category
- Managing holdbacks on both what you’re owed and what you owe
- Handling GST/HST at the right time
- Reporting subcontractor payments to the CRA
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Holdbacks: How to Track Them and When They’re Taxable
A holdback (or retainage) is a portion of a contract often around 10% under provincial builders’ lien rules withheld until the work is complete and the lien period passes. Two sides to track:
- Receivable holdbacks: money others hold back from
- Payable holdbacks: money you hold back from your
For income tax, holdbacks are generally included in income when they become receivable under the contract/lien legislation (not necessarily when cash arrives). Track them in separate accounts so they don’t distort your receivables and so you don’t accidentally under- or over-report income.
GST/HST Timing on Progress Billing and Holdbacks
GST/HST on construction has its own timing rules:
- On progress payments, GST/HST generally becomes collectible on the earlier of when payment is made or the invoice is issued/due.
- On holdbacks, the CRA provides relief: GST/HST on a holdback amount is typically not payable until the holdback is released (or the lien period expires) so you’re not remitting tax on money you haven’t received yet.
Getting this timing wrong means either paying GST/HST too early (hurting cash flow) or too late (risking interest and penalties).
T5018 | Reporting Payments to Subcontractors
If your business’s primary activity is construction and you pay subcontractors for construction services, the CRA requires a T5018 Statement of Contract Payments. Key points:
- Report total payments (including GST/HST) to each subcontractor over your reporting period.
- File it annually (you choose a calendar or fiscal-year basis).
- It helps the CRA catch subs who under-report income so missing filings draw attention.
Keep subcontractor names, business numbers, and payment totals organized all year to make this painless.
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Employee vs Subcontractor (CRA Classification Risk)
This is one of the biggest audit risks in the trades. Calling someone a “subcontractor” doesn’t make them one the CRA looks at the real relationship:
| Factor | Points to employee | Points to subcontractor |
| Control over how/when work is done | You direct it | They decide |
| Tools/equipment | You provide | They provide |
| Financial risk / profit opportunity | None | Yes |
| Ability to subcontract/hire helpers | No | Yes |
| Integration into your business | Fully integrated | Independent |
Misclassifying employees as subs can mean back CPP/EI, penalties, and interest. When in doubt, get a ruling or professional advice.
Job Costing & Progress Billing Basics
Job costing means tracking every dollar of labour, materials, equipment, and sub costs against each specific project. Do it well and you’ll know your true margin per job do it poorly and profitable jobs quietly subsidize money-losers. Pair it with progress billing (invoicing as milestones are hit) to keep cash flowing during long projects and to match revenue with the work performed.
Drowning in holdbacks, T5018s, and job costs? Maxpro Financials does bookkeeping and tax for construction and trades businesses clean job costing, correct GST/HST timing, and on-time CRA filings so you can focus on the build. 👉 Book a free consultation at maxprofinancials.ca.
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Common Bookkeeping Mistakes in Construction
- Ignoring job costing — not knowing which jobs actually make money.
- Mishandling holdbacks — distorting income and GST/HST.
- Missing T5018 filings — an easy CRA red flag.
- Misclassifying workers — the costly employee-vs-sub trap.
- Mixing personal and business — messy books and missed deductions.
- Poor cash-flow planning — long jobs and holdbacks strain cash if unmanaged.
- Falling behind on GST/HST remittances — interest and penalties add up.
FAQ
When is a construction holdback taxable?
Generally when it becomes receivable under the contract or lien rules often before you actually receive the cash. Track holdbacks separately to report them correctly.
Do I charge GST/HST on holdbacks right away?
No, GST/HST on holdbacks is typically not payable until the holdback is released or the lien period ends, which protects your cash flow.
What is a T5018 and who files it?
It’s the Statement of Contract Payments. Construction businesses that pay subcontractors for construction services must file it annually with the CRA.
How do I know if my worker is an employee or subcontractor?
The CRA looks at control, tools, financial risk, and integration not just the label. Misclassification carries back-taxes and penalties.
What’s the best way to track project profitability?
Job costing assigning all labour, materials, and sub costs to each project so you see true margins, paired with progress billing.
Do I need accounting software for a trades business?
It helps a lot. Software with job costing (or an accountant who sets it up) makes holdbacks, billing, and GST/HST far easier to manage.
What happens if I miss a T5018 deadline?
You can face penalties, and missing filings can flag your business for CRA review. File on time and keep sub records organized.
Can I deduct tools and equipment?
Yes, tools and equipment are deductible, often through Capital Cost Allowance (depreciation) for larger assets, with some small tools expensed directly.