Methodology
How we turn official pages into a calculator you can audit.
Every threshold in this project is a versioned data point with a source URL, a review date and a verification status. The goal is not to look authoritative; it is to make the evidence easy to check.
Dataset version
v2026.11.1
Last reviewed
Nov 15, 2026
Source-checked rules
4 / 20
01 · Sources
Primary sources first. Secondary sources only for context.
Each rule names a primary source from the tax authority or ministry responsible for the rule. Secondary sources are used to explain a condition, not to establish the threshold amount.
The source URL, publisher, title and review date are stored in src/data/taxRules.json. The schema rejects non-HTTPS URLs and requires every rule to have a primary source.
What we do not do
- We do not treat a blog post, accounting-firm summary or AI answer as the source of a threshold.
- We do not silently overwrite a verified amount when a scraper sees a different number.
- We do not claim that a general threshold covers every product, state or business structure.
02 · Verification
Three visible states, no ambiguous “accurate” badge.
A reviewer fetched the official page during the review window and confirmed the amount and measurement basis.
4 rules
A reviewer checked the rule against the linked official source, but the current window did not include an automated fetch.
16 rules
A source or rule change is suspected. The rule is withheld from publication until a reviewer resolves the evidence.
0 published
The weekly automation is deliberately conservative. It extracts candidate amounts from the configured official page, checks that the candidate appears in the page text, compares it with the stored amount, and requires a corroborating signal before proposing a change.
An LLM may help classify the surrounding sentence, but it cannot invent a threshold. If the evidence is ambiguous, the automation writes a review report and leaves the published dataset untouched.
03 · Calculation
Transparent arithmetic, explicit assumptions.
Threshold position
Your annual sales are converted to the rule currency, then divided by the published threshold. The result drives the three semantic states: below 75%, 75–99.99%, and 100%+.
ratio = sales / threshold Tax estimate
Tax-added mode multiplies net sales by the planning rate. Tax-included mode extracts the tax portion from a gross price.
tax = sales × rate / (1 + rate) Growth projection
The registration clock assumes constant month-over-month growth and solves for the first month the annual run-rate crosses the threshold. It is a scenario, not a forecast.
months = ln(threshold / sales) / ln(1 + growth) Fee Radar
FX spread, payout fees and an annual compliance baseline are editable assumptions in the site config. The model does not claim to know your actual provider pricing.
drag = sales × (fx + payout) + compliance All amounts use the site FX baseline dated Nov 1, 2026. Currency conversion is a planning aid, not a live quote. Tax rates are standard-rate defaults; reduced rates and exemptions are documented on each calculator page.
04 · Comparison
Why a cross-market comparison can mislead — and how we label it.
Comparing thresholds requires converting different currencies to one display currency. We use a dated USD-based FX table and show the date wherever the comparison appears. The comparison sorts converted thresholds, not the nominal local amounts.
Measurement windows are not standardized. A rolling 12-month test, a calendar-year test, a four-quarter test and a two-prior-year test are not interchangeable. Each rule stores its basis and the calculator repeats it next to the threshold.
Non-resident regimes can override the headline number. The UK NETP rule, EU OSS threshold, Singapore OVR regime and Australia's simplified GST registration are examples where a cross-border seller may register before the domestic threshold.
05 · Registration checklist
Before you file, gather the boring documents.
- 01
Entity and incorporation documents
Legal name, registration number, registered address and directors or beneficial owners.
- 02
Evidence of local activity
Contracts, invoices, warehouse or fulfilment evidence, and customer-location records.
- 03
Tax representative decision
Confirm whether a fiscal representative, local agent or security deposit is required.
- 04
Invoicing and e-invoicing setup
Check mandatory fields, clearance requirements and whether a certified provider is needed.
- 05
Filing calendar and payment method
Registration is not the end state. Confirm the first return period and local payment rails.
- 06
Price and margin reset
Decide whether to absorb tax, reprice, or change your customer mix before the effective date.
06 · Buyer checklist
How to evaluate a tax or compliance tool.
- Jurisdiction coverage: does it cover the countries and US states where you actually have customers, not just the ones in the marketing screenshot?
- Registration vs filing: some tools calculate tax, some register you, some file returns. Confirm which obligation you are outsourcing.
- Evidence and audit trail: can you export the customer-location evidence and calculation history behind each filing?
- Exit cost: who owns the registration numbers and historical records if you switch providers?
- Pricing transparency: per-return fees, per-registration fees and FX spreads should be separable from the subscription.
07 · Operator checklist
The monthly operating rhythm.
Monthly
- Reconcile sales by customer country and channel.
- Check the threshold dashboard for any market above 75%.
- Review marketplace facilitator statements.
Quarterly
- Re-test rolling windows and growth assumptions.
- Confirm filing frequencies and rate changes.
- Review FX exposure and payout fees.
Before launch
- Map product taxability and place-of-supply rules.
- Set invoice fields and tax-inclusive pricing policy.
- Document customer-location evidence collection.
On a rule change
- Link the official source and effective date.
- Update prices and checkout logic before the date.
- Record the decision in the changelog.
08 · Affiliate policy
Monetization never changes the math.
Affiliate cards are disabled by default. The neutral state is not a placeholder: it is the intended reading experience until a partner has been reviewed for relevance, pricing transparency and jurisdictional fit.
When enabled, partner cards are labeled, use rel="sponsored nofollow noopener", and are separated from calculator results. No partner can pay to change a threshold, rate, verification status or FAQ answer.
The entire affiliate system is controlled by two booleans and a slot configuration in src/config/site.config.json. Turning it on does not require a code change or redeploy of the calculator logic.
Disclosure template
Some links may be affiliate links. We may earn a commission at no extra cost to you. Affiliate partners never influence our tax data or calculator results.
Found a threshold that has changed?
Send the official URL and the amount. We log every accepted correction.