Three weeks from today, BC's Provincial Sales Tax expands to cover architectural, engineering, and geoscience services, along with security services. If your firm bills any of these services in British Columbia, October 1, 2026 is not a distant compliance date anymore — it's the next invoice you send.
What's actually changing
The BC government's Notice 2026-001 to providers of professional services sets out the mechanics for architectural, engineering, and geoscience services specifically: PST does not apply to the full professional fee. It applies to 30% of the purchase price. At the standard 7% PST rate, that works out to an effective rate of 2.1% on the total invoice. Security services are also being brought into PST from the same date.
This sits alongside the accounting and non-residential real estate services expansion we covered in our BC PST rate guide — October 1, 2026 is one expansion date bringing several service categories into scope together, not a series of separate changes spread across the year.
The math on a real invoice
Here's how the 30%-of-price base plays out on a $10,000 engineering fee:
| Line | Amount |
|---|---|
| Professional fee | $10,000.00 |
| Taxable base (30% of fee) | $3,000.00 |
| PST (7% of taxable base) | $210.00 |
| Total PST-inclusive invoice | $10,210.00 |
Two ways to check the number: multiply the full $10,000 by the effective 2.1% rate directly, or multiply the $3,000 taxable base by the standard 7% rate. Both land on $210. If your billing system can't natively apply a 30%-of-price base, configuring a flat 2.1% PST line on the full fee produces the identical result.
Three weeks to get ready
With the date this close, work through this in order:
- Registration. If your firm isn't already PST-registered, register before your first taxable sale under the new rules — see our BC PST registration guide for the eTaxBC process.
- Invoice templates. Add a 2.1% PST line item and, once registered, your PST number.
- Billing/practice-management system. Test whichever configuration your system uses (30%-of-price base, or a flat 2.1%) against the worked example above before it touches a client invoice.
- Engagement letters and quotes. Update standard wording so new engagements starting on or after October 1 reflect the tax correctly.
- Client communication. Tell affected clients before the first PST-inclusive invoice lands, not after.
Work that spans the date
If you have an engagement that starts before October 1, 2026 and gets billed after (or the reverse), don't assume either date automatically controls. The confirmed facts published so far describe the rate and the taxable base, not a specific transitional rule for straddling engagements — that depends on how performance timing versus billing timing is treated, and it's worth confirming directly with the ministry or your accountant before you invoice a transitional engagement.
Where to go deeper
Our full write-up covers who's caught, the worked example in more detail, and what stays genuinely unsettled: BC PST on professional services (October 1, 2026). For registration and filing mechanics, see our BC PST registration guide and BC PST filing and remittance guide.
RN Canada helps architectural, engineering, geoscience, and security firms register for BC PST, configure invoicing for the new 2.1% effective rate, and update client-facing wording ahead of October 1, 2026. See our GST, HST, and PST service.