If you're a contractor in Canada — whether you're in construction, trades, renovation, or general contracting — your bookkeeping has challenges that most small businesses don't face.

Project-based income, subcontractor payments, WCB premiums, holdbacks, and complex GST/HST rules make contractor bookkeeping more involved than a typical service business. And getting it wrong can mean CRA penalties, cash flow problems, and missed deductions that cost thousands.

Here's what every Canadian contractor needs to know about keeping their books right.

T4A and T5018 Reporting Requirements

If you pay subcontractors, the CRA wants to know about it — and the reporting requirements are specific to the construction industry.

T5018 — Statement of Contract Payments

Construction businesses must file T5018 slips reporting payments made to subcontractors. This applies if your primary source of income (more than 50%) is from construction activities.

Key details:

• File annually, within 6 months of your fiscal year-end
• Report all payments to subcontractors regardless of amount
• Include the subcontractor's name, address, SIN or business number, and total amount paid
• Failure to file can result in penalties of $25/day per slip, minimum $100, maximum $2,500

T4A — Statement of Pension, Retirement, Annuity, and Other Income

If you pay subcontractors who are not incorporated and are not in the construction industry, you may need to issue T4A slips for fees, commissions, or other amounts.

Your bookkeeper should:

• Track all subcontractor payments separately by vendor
• Collect W-8BEN or business registration info from every subcontractor before paying them
• Maintain records of SIN/BN for each subcontractor
• Prepare T5018 or T4A slips and file them on time

GST/HST on Construction Services

Construction GST/HST has specific rules that differ from standard services:

New residential construction — GST/HST applies to the full amount. Buyers may be eligible for the GST/HST New Housing Rebate, but that's their claim, not yours.

Renovations — GST/HST applies to renovation services. The distinction between a "renovation" and a "repair" matters for some provincial rebate programs.

Real property — Sales of new or substantially renovated real property are taxable. Sales of used residential property are generally exempt.

Self-supply rules — If you build or substantially renovate a property and then rent it out (rather than selling), you may be deemed to have sold it to yourself and must remit GST/HST on the fair market value.

Input Tax Credits (ITCs): You can claim ITCs on the GST/HST you pay on materials, subcontractor fees, equipment rentals, and other business expenses. Proper bookkeeping ensures you capture every ITC — this directly reduces the GST/HST you owe.

Job Costing: Know If Each Project Is Profitable

General bookkeeping tells you if your business is profitable overall. Job costing tells you if each individual project is profitable — and that's the information that actually helps you make better decisions.

Effective job costing tracks, for each project:

• Materials — All materials purchased for the job
• Labour — Hours worked by employees on the job, at their fully loaded cost (wages + benefits + WCB)
• Subcontractor costs — All sub payments allocated to the project
• Equipment — Rental costs or allocated ownership costs for equipment used
• Overhead allocation — A proportional share of your fixed costs (office, insurance, vehicle)

When you know the true cost of each job, you can:

• Identify which types of projects are most profitable
• Spot jobs that went over budget and understand why
• Price future jobs more accurately
• Stop taking on work that consistently loses money

Most accounting software supports job costing or project tracking. QuickBooks Online has Projects, and Xero has Tracking Categories. Your bookkeeper should set these up and ensure every transaction is tagged to the correct project.

WCB (Workers' Compensation) Premiums

In most Canadian provinces, contractors are required to carry Workers' Compensation coverage — both for employees and, in some provinces, for themselves as owners.

WCB premiums are based on your assessable payroll and your industry classification rate. Construction trades typically have higher rates than office-based businesses due to injury risk.

Bookkeeping implications:

• WCB premiums must be tracked as a separate expense
• Premiums are typically remitted quarterly or annually based on estimated payroll, with a year-end adjustment
• If you hire subcontractors who don't have their own WCB coverage, you may be liable for their premiums
• Keep certificates of clearance from subcontractors showing their WCB is current

Holdbacks and Retainage

In construction, it's common for clients to hold back a percentage (typically 10%) of each progress payment until the project is complete and a holdback period has passed. This creates a bookkeeping challenge:

• Invoice the full amount, including holdback
• Record the holdback as accounts receivable — it's money owed to you, just not yet due
• Release the holdback from AR when it's paid after the holdback period
• Manage cash flow knowing that 10% of your invoiced revenue won't arrive for months

Failing to account for holdbacks properly distorts your cash flow projections. Many contractors get surprised by cash shortages because they've been looking at invoiced revenue rather than collected revenue.

Cash Flow Management for Contractors

Contractor cash flow is inherently lumpy. Large project deposits followed by weeks of expenses before the next progress payment. Seasonal slowdowns in winter. Holdbacks delaying full payment for months.

Cash flow best practices:

• Invoice promptly — Don't wait until the end of the month to invoice completed work. Progress billing keeps cash flowing.
• Separate accounts — Maintain a dedicated account for GST/HST and payroll remittances so that money isn't accidentally spent on materials.
• Track holdbacks — Know exactly how much is being held back and when it's due for release.
• Build a cash reserve — Target 2-3 months of operating expenses, especially if your work is seasonal.
• Review AR weekly — Follow up on overdue invoices immediately. In construction, slow payment is common — but acceptable "slow" and "not paying" are different.

CRA Audit Risks for Contractors

The construction industry is one of the CRA's priority audit sectors. Reasons include:

• High cash transaction volumes
• Subcontractor payments (are they really subcontractors or should they be employees?)
• T5018 compliance
• Input tax credit claims on materials and equipment

Proper bookkeeping is your best defence. Keep detailed records, file all required slips on time, maintain clear documentation of subcontractor relationships, and ensure every expense has a receipt.

Get Your Contractor Books Right

Contractor bookkeeping is too complex to wing it. The combination of CRA reporting requirements, job costing, holdbacks, and construction-specific tax rules means that a bookkeeper who understands the construction industry will save you money and keep you compliant.

At Path 2 Profit Bookkeeping, we work with contractors who need more than basic transaction entry. Our monthly bookkeeping services include job costing setup, subcontractor payment tracking, GST/HST management, and CRA compliance reporting.

Book a Free Accounting Consult — we'll review your current setup and show you where the gaps are before the CRA finds them.