Sõiduki registreerimistasu

Estonian motor-vehicle registration fee (mootorsõidukimaks, registreerimistasu)

Transpordiamet publishes a documented JSON API behind its public tax calculator. It is the only unauthenticated, machine-readable route into liiklusregister data — the vehicle background check and the calculator's own web form are both bot-gated, and a person's vehicle data needs ID-login. Read ## Limits.

Vetted module (use this first)

soidukimaks.mjs ships in https://kodanikukratt.ee/kratt-agent.tar.gz (plain ESM, Node 22+) and is re-verified against the live source:

import { show } from "./kratt.mjs";
import { registrationFee } from "./soidukimaks.mjs";

const r = await registrationFee({
  category: "M1", bodyworkCode: "UNIVERSAAL", seats: 8,
  co2wltp: 183, technPermMaxLadenMass: 2790,
  initialRegDate: "2021-01-12", regFeeCalcDate: "2026-01-01",
});
show({
  kokku: r.totalPrice, baas: r.basePrice, co2: r.co2Price, mass: r.massPrice,
  vanusekoefitsient: r.ageCoef, valuuta: r.currency, sisend: r.inputs, page: r.page, note: r.note,
});

• registrationFee({...}) passes every parameter in ## Retrieve straight through, so anything documented there works. It refuses a category the fee does not exist for (only M1, M1G, N1, N1G) rather than letting the API answer an unexplained 400 — and that refusal is not a fee of zero, it means the vehicle is outside this tax.
• A missing parameter comes back as an error naming what is required, because the API's own 400 says only "Invalid data". Ask the citizen for the value; never invent a mass, power or CO2 figure.
• inputs echoes exactly what was sent. Restate those assumptions in the answer — a fee computed from a guessed täismass is a wrong number that looks authoritative.
• note says which half of the tax this is. It is the one-off registreerimistasu, not the annual mootorsõidukimaks, and it applies no exemptions at all.
• registrationFeeByIdentifier({regNr}) / ({vinCode}) is the same shape for one registered vehicle. Use it only with an identifier the citizen supplied about their own car; HTTP 422 means the register has no such vehicle, and nothing else about that vehicle comes back with the fee.

claim HTTP 422 means the register has no such vehicle
GET https://apimsm.transpordiamet.ee/v2/msm/regTasu/by-vehicle-identifier?regNr=000XXX
expect-status 422
expect /Vehicle not found/
# The control is the technical-parameter endpoint on the same API, which must
# still price a vehicle. Without it, an API answering 422 to everything would
# read as "no such vehicle" for every plate a citizen ever gives us.
control GET https://apimsm.transpordiamet.ee/v2/msm/regTasu/by-technical-parameters?category=M1&bodyworkCode=UNIVERSAAL&co2wltp=183&technPermMaxLadenMass=2790&initialRegDate=2021-01-12&seats=8&regFeeCalcDate=2026-01-01

The endpoints below are the fallback if a module call throws.

Access

Base: https://apimsm.transpordiamet.ee/v2/msm/regTasu/

No authentication, no API key, JSON responses. Documented by Transpordiamet in "Mootorsõidukimaksu avaliku kalkulaatori registreerimistasu ja omanikuvahetustasu arvutamise API V2 täiendatud juhend" (PDF, linked from https://www.transpordiamet.ee/soidukid-ja-maanteeliiklus/soidukid/mootorsoidukimaks).

Retrieve

Three GET endpoints, all returning the same body:

GET /v2/msm/regTasu/by-vehicle-identifier?regNr=287HJG
GET /v2/msm/regTasu/by-vehicle-identifier?vinCode=WDF63960313149509
GET /v2/msm/regTasu/by-technical-parameters?category=M1&bodyworkCode=UNIVERSAAL&co2wltp=183&technPermMaxLadenMass=2790&initialRegDate=2021-01-12&seats=8&regFeeCalcDate=2026-01-01

Response, all amounts in euros:

{"totalPrice":504.96,"co2Price":204.96,"massPrice":0.00,"basePrice":300.00,"ageCoef":0.56}

co2Price and massPrice are already multiplied by ageCoef; ageCoef is derived from whole years between initialRegDate and regFeeCalcDate.

Parameters for by-technical-parameters:

• category — required; the fee exists only for M1, M1G, N1, N1G.
• initialRegDate, regFeeCalcDate — always required, YYYY-MM-DD.
• seats — required for M1/M1G.
• technPermMaxLadenMass (täismass), kerbMass (tühimass), maximumNetPower (kW, combustion engine only) — required unless the vehicle is electric and a CO2 figure is present.
• co2wltp — required unless electric; co2nedc — required when WLTP is missing. With several values, take the smallest non-zero one.
• engineType — BENSIIN, BENSIIN_HYBRIID, ELEKTER, DIISEL, GAAS, BENSIIN_KATALYSAATOR, DIISEL_HYBRIID, LPG, CNG.
• fuelCombination — VESINIKKYTUS, KAHEKYTUSELINE, MITMEKYTUSELINE, YHEKYTUSELINE, ELEKTRISOIDUK, HYBRIIDSOIDUK, SEGAKAHEKYTUSELINE, SEGAKYTUSELINE.
• fuelType — petrol side BENSIIN, ETANOOL, HE-15; diesel side DIISEL, BIODIISEL, XTL, CNG_DIISEL, LNG_DIISEL, LNG_CNG_DIISEL.
• hybridType — NOVC_FCHV, NOVC_HEV, OVC_HEV, OVC_FCHV; needed when WLTP and NEDC are both missing on a hybrid.
• bodyworkCode — only matters when the body is ELAMU.

Return

Preserve every component (totalPrice, co2Price, massPrice, basePrice, ageCoef), the identifier or parameter set used, regFeeCalcDate, and the exact URL fetched. Say which half of the tax the number is: this is the one-off registreerimistasu / omanikuvahetustasu, not the annual tax.

Limits

• Registration fee only. The annual tax (aastamaks) is administered by EMTA and has no published public API. Its objects, rates and formulas are in mootorsõidukimaksu seadus — fetch the in-force text via legal-acts-data and cite the § you printed instead of computing an annual figure yourself.
• The API does not apply exemptions: it returns a fee even for an alarmsõiduk, a diplomatic vehicle or a defence-sector vehicle. It also ignores the statutory cases where no fee arises (buying a leased car out of the lease when already the responsible user; registering an inherited vehicle) — check those against the act.
• No vehicle technical data, owner, restrictions or usage history. "Sõiduki taustakontroll" (https://eteenindus.mnt.ee/public/soidukTaustakontroll.jsf) is gated by Google reCAPTCHA v3: a scripted POST gets the empty search form back, with no result and no error. Never present that empty form as a retrieval. The owner's own vehicle data needs ID-card / Mobiil-ID login in Transpordiamet e-teenindus, and third-party liiklusregister data is released only under https://www.transpordiamet.ee/liiklusregistrist-juurdepaasupiiranguga-andmete-valjastamine.
• A plate or VIN identifies one person's car. Use those two endpoints only with an identifier the user supplied themselves.

Verify

• Require HTTP 200 with JSON containing numeric totalPrice and basePrice, and state the figure only from a printed response body.
• HTTP 422 {"errorMessage":"Vehicle not found"} — the plate or VIN is not in the register (or plate and VIN belong to different vehicles). Report that, do not retry with a guessed identifier.

claim HTTP 422 `{"errorMessage":"Vehicle not found"}` — the plate or VIN is not in the register
GET https://apimsm.transpordiamet.ee/v2/msm/regTasu/by-vehicle-identifier?vinCode=00000000000000000
expect-status 422
expect /Vehicle not found/
# A VIN, not a plate, because the claim covers both and the two are separate
# lookups. The control prices a vehicle from technical parameters on the same
# API: a 422-to-everything day must not read as "the register has no such VIN".
control GET https://apimsm.transpordiamet.ee/v2/msm/regTasu/by-technical-parameters?category=M1&bodyworkCode=UNIVERSAAL&co2wltp=183&technPermMaxLadenMass=2790&initialRegDate=2021-01-12&seats=8&regFeeCalcDate=2026-01-01

A placeholder VIN is the exception and it fails quietly instead: vinCode=XXXXXXXXXXXXXXXXX (any run of X) answers HTTP 200 with every price 0.00 and ageCoef: null (checked 2026-08-02), which reads as "this car owes nothing" rather than "no such car". A total of zero next to a null ageCoef is not a fee — never state it as one, and never send a VIN the citizen did not give you.

• HTTP 400 {"errorMessage":"Invalid data"} — a required parameter is missing. Name the missing parameter and ask; do not invent a mass, power or CO2 value.

claim HTTP 400 `{"errorMessage":"Invalid data"}` — a required parameter is missing
GET https://apimsm.transpordiamet.ee/v2/msm/regTasu/by-technical-parameters?category=M1&initialRegDate=2021-01-12&regFeeCalcDate=2026-01-01
expect-status 400
expect /Invalid data/
# Same request as the control, minus seats/co2wltp/technPermMaxLadenMass. If the
# API ever starts pricing an incomplete parameter set, the number it returns is
# computed from values nobody supplied — which is why this one is pinned.
control GET https://apimsm.transpordiamet.ee/v2/msm/regTasu/by-technical-parameters?category=M1&bodyworkCode=UNIVERSAAL&co2wltp=183&technPermMaxLadenMass=2790&initialRegDate=2021-01-12&seats=8&regFeeCalcDate=2026-01-01

Module API

registrationFee({category, initialRegDate, regFeeCalcDate, co2wltp, technPermMaxLadenMass, seats, engineType, ...}) -> {source, page, currency, totalPrice, basePrice, co2Price, massPrice, ageCoef, inputs, note}