Canada GST/HST Threshold Watch — connector documentation

• MCP endpoint: https://ca-gst-thresholds.connectorbay.com/mcp
• REST API: POST https://ca-gst-thresholds.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://ca-gst-thresholds.connectorbay.com/openapi.json
• Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
• Authentication: none required. An optional Authorization: Bearer <key> raises rate limits.
• Health: https://ca-gst-thresholds.connectorbay.com/health · Tool schemas: https://ca-gst-thresholds.connectorbay.com/tools.json
• Publisher: Unify Dynamics LLC · connectorbay.com/ca-gst-thresholds · agent@connectorbay.com

What Canada GST/HST Threshold Watch is for

Checks quarterly taxable supplies against the GST/HST small-supplier threshold ($30,000 in a single calendar quarter or over four consecutive quarters), shows what the CRA text says about when registration takes effect, which reporting period applies by annual taxable supplies ($1.5 million and $6 million breakpoints), whether the quick method limit ($400,000) is met, the electronic filing and $10,000 electronic payment rules, the same test with Revenu Quebec wording for GST and QST, and a weekly threshold-watch summary with headroom and a run-rate projection. Every threshold names its source, page date and verification level. Simplified: associated-person, exempt-supply and public-service-body detail are not modelled.

Ask your assistant things like:

• "My taxable sales were 9000, 11000, 12000 and 9500 in the last four quarters: am I still a small supplier?"
• "I passed 30,000 in sales on 14 August 2026 within one quarter: by when must I be registered for GST/HST?"
• "My annual taxable supplies are 2.3 million dollars: how often must I file my GST/HST return?"
• "My sales including HST were 385,000 last year: can I use the quick method of accounting?"
• "Does my 12,400 GST/HST remittance have to be paid electronically?"
• "Where am I against the 30,000 small supplier line this quarter and when might I cross it?"
• "I sell in Quebec: do my quarterly sales make me a small supplier for GST and QST?"

What it does

• check_small_supplier: Test quarterly taxable supplies against the 30,000 single-quarter and four-consecutive-quarter small-supplier rules and show the headroom.
• registration_deadline: When registration takes effect and the 29-day application window after the threshold is crossed in one quarter or over four quarters.
• assigned_reporting_period: Annual, quarterly or monthly GST/HST reporting period by annual taxable supplies (1.5 million and 6 million breakpoints), with election options and filing deadline rules.
• quick_method_eligible: Check annual supplies including GST/HST against the quick method limit of 400,000 and describe the credit and election routes.
• quebec_small_supplier_check: The same small-supplier test with Revenu Quebec wording for GST and QST, including activities that must register whatever the sales.
• efile_epay_rules: Mandatory electronic filing and the 10,000 electronic payment rule for GST/HST, with a check of a payment amount.
• threshold_watch_report: Weekly summary: headroom to the 30,000 lines, a run-rate projection of when a line is crossed, and what the rules say happens then.

Data sources

• https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/when-register-charge.html
• https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/rc4022/general-information-gst-hst-registrants.html
• https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/file-gst-hst-return/reporting-requirements-deadlines.html
• https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/rc4058/quick-method-accounting-gst-hst.html
• https://www.revenuquebec.ca/en/citizens/consumption-taxes/taxable-zero-rated-or-tax-exempt-goods-and-services/gst-and-qst/other-situations/details-concerning-small-suppliers/
• https://www.revenuquebec.ca/en/businesses/consumption-taxes/gsthst-and-qst/registering-for-the-gst-and-qst/

Reference data from official sources (canada.ca, revenuquebec.ca); every answer states its source, date and validity period.

What it is not

Canada GST/HST Threshold Watch is independent; not affiliated with, endorsed by or operated by any government body, central bank, standards body or scheme operator. Names of rails, schemes and standards are used only to say what a tool works with. It is read-only: it never sends, pays, files or signs anything for you, and it never looks up private individuals.

Not advice. General information only, not legal, tax, accounting or payment advice. Canada GST/HST Threshold Watch is an independent tool: it is not affiliated with, endorsed by or operated by any government body, central bank, standards body or scheme operator. Rates, thresholds and rules change; check the cited official source and confirm with a qualified professional before you rely on a result.

Built for: Canada. Languages: English.

Tools

Look up & validate

check_small_supplier — Test quarterly taxable supplies against the 30,000 single-quarter and four-consecutive-quarter small-supplier rules and show the headroom. Use for "My taxable sales were 9000, 11000, 12000 and 9500 in the last four quarters: am I still a small supplier?". Args: quarters, latest_quarter_end, public_service_body.

Reference & guides

registration_deadline — When registration takes effect and the 29-day application window after the threshold is crossed in one quarter or over four quarters. Use for "I passed 30,000 on 2026-08-14 in one quarter: what date must I be registered by?". Args: trigger, on_date.

assigned_reporting_period — Annual, quarterly or monthly GST/HST reporting period by annual taxable supplies (1.5 million and 6 million breakpoints), with election options and filing deadline rules. Use for "My annual taxable supplies are 2,300,000: what GST/HST reporting period applies?". Args: annual_taxable_supplies.

quick_method_eligible — Check annual supplies including GST/HST against the quick method limit of 400,000 and describe the credit and election routes. Use for "My sales including HST were 385,000 last year: can I use the quick method?". Args: annual_supplies_including_tax.

quebec_small_supplier_check — The same small-supplier test with Revenu Quebec wording for GST and QST, including activities that must register whatever the sales. Use for "I sell in Quebec: do my quarterly sales make me a small supplier for GST and QST?". Args: quarters, latest_quarter_end.

efile_epay_rules — Mandatory electronic filing and the 10,000 electronic payment rule for GST/HST, with a check of a payment amount. Use for "My GST/HST remittance is 12,400: does it have to be paid electronically?". Args: payment_amount, on_date.

threshold_watch_report — Weekly summary: headroom to the 30,000 lines, a run-rate projection of when a line is crossed, and what the rules say happens then. Use for "Where am I against the 30,000 small-supplier line this quarter and when might I cross it?". Args: previous_quarters, current_quarter_to_date, as_of_date, public_service_body.

Conventions

• Read-only. Every tool reads public data or computes; nothing is written anywhere and nothing about the user is stored.
• Result envelope. ok: true with data, or ok: false with a structured error (bad_input, not_found, upstream_error). degraded lists optional sources that were unreachable.
• Rate limits. Free tier 60 tool calls/minute and 300/day per user (keyed on the user identifier supplied by the host agent, else client IP); Pro keys raise this. Over-limit calls return HTTP 429 with Retry-After. initialize and tools/list are never counted.

Support

agent@connectorbay.com · connectorbay.com/ca-gst-thresholds/support