Overview
Commenda’s exposure engine evaluates your transaction data against registration threshold rules for jurisdictions worldwide. It determines whether your business has exceeded — or is approaching — the point where you must register to collect and remit indirect tax in a given jurisdiction.
The exposure engine supports:
- US economic thresholds — state-level sales and transaction count thresholds (post-Wayfair)
- Canada GST/HST — federal and provincial thresholds
- UK VAT — standard UK VAT registration threshold
- EU country-level VAT — per-country thresholds for EU member states
- EU trade bloc rules — Union OSS, Non-Union OSS, and IOSS schemes with cross-border scope
Key concepts
Exposure rules
Each jurisdiction has one or more exposure rules that define when registration is required. A rule specifies:
| Field | Description |
|---|
exposure_rule_id | Unique identifier for the rule |
exposure_type | The type of tax obligation (e.g., EXPOSURE) |
threshold_type | Whether the threshold is based on SALES, TRANSACTIONS, or SALES_OR_TRANSACTIONS |
sales_threshold | Revenue amount that triggers registration |
transactions_threshold | Transaction count that triggers registration |
evaluation_period | Time window for measuring activity (e.g., PRECEDING_12_MONTHS, PREVIOUS_OR_CURRENT_CALENDAR_YEAR) |
Multi-rule jurisdictions
Some jurisdictions have multiple rules that apply based on your business’s establishment status. For example, an EU member state may have:
- A resident rule for businesses with a physical establishment in that country (e.g., office, warehouse)
- A non-resident rule for businesses selling into the country without a local establishment
The engine automatically selects the applicable rules based on your registered locations.
Location-based scope
Rules define which transactions count toward the threshold based on the geographic relationship between buyer and seller:
| Scope | Description |
|---|
DESTINATION | Transactions where the buyer is in the rule’s jurisdiction |
WORLDWIDE | All transactions regardless of destination |
INTRA_COMMUNITY | Cross-border transactions within a trade bloc (e.g., EU seller to EU buyer in a different member state) |
IMPORT | Transactions where the seller is outside the trade bloc and the buyer is inside |
Exclusions
Certain transactions are automatically excluded from threshold calculations when the rule defines exclusions:
- Marketplace transactions — sales facilitated by a marketplace that collects tax on your behalf
- B2B transactions — sales to business customers identified by a business identification number (e.g., VAT number), which are typically subject to reverse charge
- Resale transactions — sales to customers with valid resale certificates
- Product taxability — specific product categories excluded per jurisdiction rules (e.g., tangible goods excluded from digital services thresholds)
- Destination registered — transactions to jurisdictions where you are already registered
Max transaction value (IOSS)
The EU Import One-Stop Shop (IOSS) scheme applies only to consignments valued at or below €150. Transactions exceeding this cap are excluded from IOSS threshold tracking. An invoice exactly equal to the cap is included.
Querying exposure data
Use the registration thresholds endpoint with v2=true to retrieve exposure data across all supported jurisdictions:
curl -X GET "https://transaction-tax.api.in.commenda.io/api/v1/nexus?corporation_id={corporation_id}&v2=true" \
-H "Authorization: Bearer <your_token>"
Response structure
The v2 response returns an array of jurisdiction objects, each representing one exposure rule evaluation:
{
"data": {
"corporation_id": "74df772f-9260-42cf-9c20-3b613b60fecd",
"jurisdictions": [
{
"jurisdiction_id": "STATE_US_NY_1036",
"jurisdiction_type": "STATE",
"exposure_type": "EXPOSURE",
"exposure_rule_id": "us_ny_economic",
"country": "US",
"subdivision": "NY",
"currency": "USD",
"rule": {
"sales_threshold": 500000,
"transactions_threshold": null,
"threshold_type": "SALES",
"evaluation_period_type": "PREVIOUS_OR_CURRENT_CALENDAR_YEAR"
},
"calculation": {
"included_sales": 320000,
"included_transactions": 1500,
"gross_sales": 350000,
"gross_transactions": 1800,
"sales_exposure_percentage": 0.64,
"transactions_exposure_percentage": 0
},
"is_nexus_breached": false
},
{
"jurisdiction_id": "TRADEBLOC_EU_3000",
"jurisdiction_type": "TRADEBLOC",
"exposure_type": "EXPOSURE",
"exposure_rule_id": "eu_union_oss",
"country": "",
"subdivision": "",
"currency": "EUR",
"rule": {
"sales_threshold": 10000,
"transactions_threshold": null,
"threshold_type": "SALES",
"evaluation_period_type": "PREVIOUS_OR_CURRENT_CALENDAR_YEAR"
},
"calculation": {
"included_sales": 8500,
"included_transactions": 42,
"gross_sales": 12000,
"gross_transactions": 60,
"sales_exposure_percentage": 0.85,
"transactions_exposure_percentage": 0
},
"is_nexus_breached": false
}
]
},
"message": "Successfully fetched nexus."
}
Response fields
Each jurisdiction object includes:
| Field | Description |
|---|
jurisdiction_id | Internal identifier for the jurisdiction. For trade bloc rules, this is the trade bloc ID (e.g., TRADEBLOC_EU_3000) |
jurisdiction_type | STATE, COUNTRY, or TRADEBLOC |
exposure_type | Type of exposure obligation |
exposure_rule_id | Identifier for the specific rule being evaluated |
country | ISO country code, empty for trade bloc-level rules |
subdivision | State or province code, if applicable |
currency | Currency of the threshold amounts |
rule | The threshold rule being applied |
calculation | Your current progress toward the threshold |
is_nexus_breached | Whether you have exceeded the registration threshold |
date_of_breach | Date when the threshold was exceeded, if breached |
A single jurisdiction may appear multiple times in the response if multiple exposure rules apply (e.g., separate rules for goods and services in France or Ireland).
Calculation fields
| Field | Description |
|---|
included_sales | Revenue counted toward the threshold after applying exclusions |
included_transactions | Transaction count after exclusions |
gross_sales | Total revenue before exclusions |
gross_transactions | Total transaction count before exclusions |
sales_exposure_percentage | Ratio of included sales to the sales threshold (0 to 1+) |
transactions_exposure_percentage | Ratio of included transactions to the transactions threshold (0 to 1+) |
Triggering a sync
The exposure engine runs automatically on a schedule. You can also trigger a manual sync for a specific corporation:
curl -X POST "https://transaction-tax.api.in.commenda.io/api/v1/internal/nexus/sync/corporation/{corporation_id}?v2=true" \
-H "Authorization: Bearer <your_token>"
Pass v2=true to run the global exposure engine. Without this parameter, only the legacy US-focused sync runs.
Physical presence
If your business has a physical establishment (office, warehouse, or other location) in a jurisdiction, the engine evaluates resident rules for that jurisdiction. Resident rules may have different thresholds or no threshold at all — physical presence can trigger an immediate registration obligation.
Register your business locations via the Locations API to ensure the engine correctly identifies which rules apply.
