GST/HST and CRA registration for a Canadian window cleaning business

Start with the business number, then attach programs

The Canada Revenue Agency issues a nine-digit Business Number (BN) as the federal identifier for a window cleaning business. GST/HST, payroll deductions, corporate income tax, and import/export are separate program accounts attached to that number, rather than separate root numbers for each tax program.

Registration is available through Business Registration Online, by phone, by mail, or through a service provider. The paper form is RC1, Request for a Business Number and Authorization for Program Accounts. The rules come from Part IX of the Excise Tax Act, and the CRA explains them in guide RC4022, General Information for GST/HST Registrants. The figures here are current as of 2026, so check them on the CRA pages. The Starting a business - Canada.ca page gives federal setup information. A business owner supplies the legal and operating names, address, ownership type, and the date the accounts should begin.

The account suffixes identify the program: RT is GST/HST, RP is payroll deductions, and RC is corporate income tax. A sole proprietor with no employees may need only a BN and RT account, while a corporation receives its own BN on incorporation. The number remains with the business unless it is closed.

Registration involves requesting the BN, adding the accounts required, setting their effective dates, and then confirming access. Voluntary GST/HST registration can begin on the registration date; mandatory registration begins on the prescribed date after the threshold-crossing quarter, and the CRA will not backdate it earlier.

A sole proprietor can operate with a BN linked to a social insurance number, while a corporation has a separate BN. Choosing between those structures is a separate decision from choosing program accounts; compare the Canadian business structures before setting up the launch sequence.

Treat the small supplier limit as a rolling checkpoint

The small supplier test uses taxable supplies across four consecutive calendar quarters, not a January-to-December total. If the total exceeds $30,000, registration becomes mandatory on the first day of the second month after the quarter in which the business crossed the limit. There is a second case. If taxable supplies pass $30,000 within a single calendar quarter, the business must charge tax on the supply that takes it over the limit and must register within 29 days of that supply.

Window cleaning and other taxable services count toward the total, and routine residential window cleaning is taxable in Canada. For example, a business crossing the limit in the quarter ending December 31 becomes registered on February 1, so taxable invoices carry GST/HST from that effective date.

An owner below the limit may register voluntarily, which can permit recovery of GST/HST paid on eligible business purchases. That choice also means charging tax to residential customers who may expect an unchanged round-number price, so account for the change when setting window cleaning prices.

Match the tax treatment to the service location

GST/HST is collected through a federal account, but the applicable rate follows the province where the supply is made. A provincial program can still require its own registration, so an RT account alone does not settle every provincial tax obligation.

Yukon, the Northwest Territories and Nunavut charge the 5% GST only, with no territorial sales tax, and the work is registered with the CRA. Ontario charges 13% HST; British Columbia combines 5% GST with 7% PST; Quebec combines 5% GST with 9.975% QST, and Revenu Quebec administers both, so a Quebec-based operator registers with it for GST and QST together. In these provinces, the federal GST/HST account does not replace separate provincial registration where PST or QST applies, so check whether the service is taxable before collecting those amounts.

Nova Scotia's HST fell from 15% to 14% on April 1, 2025. Manitoba's RST and Saskatchewan's PST mainly apply to goods and a short list of services, so do not assume either provincial tax applies to routine window cleaning without checking the relevant rule.

For work across provincial borders, use the customer's location to determine the applicable tax rather than the location where the truck is parked. Build the applicable rate and account details into the customer-facing quote template, and make the service location clear in the job records.

Keep purchase evidence attached to tax claims

Input tax credits can recover GST/HST paid on eligible business expenses, but a supplier invoice showing the supplier's tax number, amount paid, and tax charged is needed to support the claim.

Meals and entertainment are usually only half claimable, personal vehicle use must be prorated using a mileage log, and a truck or trailer is a capital asset claimed over time through capital cost allowance. The quick method instead uses a set percentage of revenue and gives up most input tax credits, so compare the method with the business's own costs.

Keep invoices with the related bookkeeping records: the CRA may review claims later, and a missing invoice can increase an assessment. Organizing purchase records alongside the bookkeeping and cash flow makes it easier to match tax collected, tax paid, and each return.

Keep an open account current between jobs

A GST/HST account creates a continuing return obligation, even for a period with no revenue. Most small window cleaning businesses file annually or quarterly; filing frequency depends on revenue, and a dormant period still requires a nil return.

Annual filers with a December 31 year end file by March 31; quarterly filers file within one month after quarter end, and monthly filers within one month after month end. Annual filers with business income as an individual file by June 15, while any balance owing is due April 30. The quarterly period applies once annual taxable supplies exceed $1.5 million, and the monthly period once they exceed $6 million, so most window cleaners will file annually. The return is Form GST34, and the CRA's how-to-file page lists available online, phone, mail, and in-person methods.

Annual filers may also need instalments when net tax owing reaches $3,000 for the year or reached that amount in the previous year. Four instalments are due, each one month after a fiscal quarter ends. Smaller errors can be corrected on a later return, while larger matters may require voluntary disclosure; late filing can bring interest and penalties.

Separate payroll and provincial obligations from RT

The first employee triggers a CRA payroll account for CPP, EI, and income tax withholding; those payroll deductions are separate from GST/HST. The remittance schedule depends on average monthly withholding, ranging from quarterly for eligible smaller remitters to more frequent schedules as withholding rises.

Ontario employers with total Ontario payroll above $1 million pay Employer Health Tax, register, and file an annual return. Workers' compensation is administered separately, including WSIB in Ontario, WorkSafeBC in British Columbia, and the Workers' Compensation Board in Alberta; confirm coverage and classification with the relevant authority or broker.

Quebec employers use CNESST for workplace health and safety and Revenu Quebec for provincial payroll remittances, so a Quebec-only operator should not copy an Ontario setup. Hiring internationally also involves Employment and Social Development Canada and may take longer than CRA registration; check the licence and compliance list before the first payroll run.

Run these checks before collecting or filing tax

A short control routine can prevent missed effective dates, unsupported claims, and overlooked accounts. Reconcile the rolling four-quarter total, check the RT start date, confirm the location and applicable rate for each job, and match claimed input tax credits to supplier invoices before preparing a return.

The seven common errors shown below include calendar-year counting, collecting before registration, relying only on a bank statement, skipping nil returns, mixing personal and business costs, overlooking provincial accounts, and failing to update business details. Use the market selection checklist alongside the records routine when planning the work mix.

Use the CRA Forms and publications page when the correct registration or election form is unclear. For work involving provincial boards, keep the tax account separate from the safety and coverage obligations described in the provincial board comparison; neither system replaces the other.