What counts as a credit vs. a raw API call?

Credits, not raw call counts, meter developer API usage. Reference and utility endpoints cost 0 credits, database lookups (tariff rates, USMCA checks) cost 0.5 credits, and AI-powered endpoints (classification, batch classify) cost 2 credits per call. A 500-credit plan is not 500 calls — it is up to 1,000 DB lookups, or 250 AI classifications, or any mix.

Are the 3 free public tools rate-limited?

No. The Tariff Rate Calculator, IEEPA Refund Estimator, and USMCA Qualification tool run without an account, without an API key, and without a call limit as of 2026-07-27 — they are the free front door, not a metered product.

What happens when a developer plan hits its credit limit?

The Free tier blocks at 100 credits with no overage. Starter, Pro, and Business tiers allow metered overage at a per-credit rate that decreases with plan size ($0.05 on Starter down to $0.02 on Business). Enterprise plans negotiate custom limits.

Is the broker (Partner Portal) billing the same as the developer API billing?

No — they are two independent systems. Brokers using the Partner Portal are billed per tool run (one run per form submission), not per API credit. Developers calling the API directly are billed per credit, where credit cost varies by endpoint type. The two never mix.

DEVELOPER API • RATE LIMITS & CREDIT COSTS

API Rate Limits & Credit Pricing

Every number below is the exact figure the API enforces — the same config the checkout and the rate limiter both read from.

Developer API tiers

Tier	Price	Credits / month	Rate limit	Overage
Free	$0	100	10/min, 100/day	Blocked, no overage
Starter	$49/mo	500	30/min	$0.05/credit
Pro	$199/mo	3,000	60/min	$0.03/credit
Business	$599/mo	12,000	150/min	$0.02/credit
Enterprise	Custom	50,000+	300/min	Custom

Credit cost by endpoint type

All 47 v1 endpoints and 21 widget endpoints are available on every paid tier — plans differ by credit volume and rate limit, not by feature access.

0 credits

Reference & utility endpoints (e.g. supported countries, usage stats)

0.5 credits

Database lookups — tariff rates, USMCA qualification, duty calculation

2 credits

AI-powered endpoints — HS classification, batch classify

3 free public tools — no key, no limit

The Tariff Rate Calculator, IEEPA Refund Estimator, and USMCA Qualification tool run without signup, without an API key, and without a call cap. They are the free front door to the product, not a metered tier.

Tariff Calculator →IEEPA Refund →USMCA Qualification →

Partner Portal (broker) billing — a separate system

Brokers using the Partner Portal are billed per tool run (one run per form submission), starting at 50 trial runs, not per API credit. This is independent of the developer tiers above — the two billing systems never mix.

Full endpoint list and authentication details: Developer Guide →