Answers

Simple statutory interest on a principal at the cited statutory-interest series rate (Actual/365)

Simple interest at the cited statutory rate (Actual/365, from inclusive, to exclusive), 2 dp with workings. Not legal advice; no compounding. Give days or from+to; bad input is refused free. receipt:true embeds an answer_receipt.

post/v1/answers/statutory-interest

Request

Base URL: https://ausref.dev
URL: https://ausref.dev/v1/answers/statutory-interest
Auth: one of:
- API key in header PAYMENT-SIGNATURE
- API key in header X-PAYMENT
- API key in header X-API-Key

Headers

X-Free-Trial'1'

Opt in to the free trial (3 calls/day/IP).

Request body

country'au' | 'fj' | 'nz' | 'pg' | 'sb' | 'to' | 'vu' | 'ws' required

ISO 3166-1 alpha-2 in this brand's catalog that holds a statutory-interest series.

principalnumber required

Principal in the country's currency. Must be a finite number greater than 0.

daysnumber

Positive day-count days. Supply this, or from and to. If both are sent and disagree, the call is 400 free.

fromstring date

Start date YYYY-MM-DD, inclusive. Required together with to when days is omitted.

tostring date

End date YYYY-MM-DD, exclusive. Day count is the UTC calendar difference to − from.

receiptboolean

Optional. Default false. When true, a paid HTTP 200 embeds an Ed25519-signed receipt (kind answer_receipt) the caller can file and later verify at /certified/public-key. Included in this answer's existing price — no extra charge. The field is omitted on unpaid 402 and on free 4xx refusals. This is not a series certified extract: GET /v1/certified/{country}/{series} is a different artifact, with its own price.

Response

Interest, the cited rate, Actual/365 workings, disclaimer and limitations. Optional property receipt (schema AnswerReceipt, kind answer_receipt) is present only when the request set receipt:true and this response is a paid HTTP 200. Unpaid 402 and free 4xx refusals do not include receipt. Not a series certified extract (GET /v1/certified/{country}/{series}).

status'ok' required

confidence_label'high' | 'medium' | 'low'

Derived from source type, verification age, stale. Rules: /label-rules

coverage_label'ready' | 'partial' | 'gap'

ready=complete, partial=limited, gap=no number. Rules: /label-rules

label_basisobject

Inputs and rule ids behind both labels

countrystring required

ISO 3166-1 alpha-2

principalnumber required

daysnumber required

Day-count days used. From the request, or the UTC calendar difference to − from.

ratenumber required

Cited series rate in percent, after the same materialization as GET /v1/{country}/statutory-interest.

rate_unit'percent' required

day_count_basis'actual/365_simple' required

interestnumber required

principal × (rate / 100) × (days / 365), rounded to 2 decimal places.

workingsstring required

The arithmetic, including the 2-decimal rounding.

disclaimerstring required

COMPUTED_DISCLAIMER. This is a computation, not a cited value and not advice.

limitationsstring[] required

Always populated. Not legal advice; the computation is over the cited series as of last_confirmed; Actual/365 simple only.

Example response

{
  "receipt": {
    "kind": "answer_receipt",
    "receipt_id": "0123456789abcdef01234567",
    "answer": "vat",
    "request": {
      "country": "za",
      "amount": 100,
      "mode": "add",
      "receipt": true
    },
    "result": {
      "status": "ok"
    },
    "cited_series": [
      {
        "country": "za",
        "series_id": "vat",
        "value": null,
        "last_confirmed": "2026-04-01",
        "source_url": null,
        "source_sha256": null
      }
    ],
    "issued_at": "2026-09-25T15:45:00.000Z",
    "limitations": [
      "This receipt is not a series certified extract (GET /v1/certified/{country}/{series}).",
      "This receipt is not legal advice. It only covers the computation over the cited series as of each series' last_confirmed."
    ],
    "signature": {
      "alg": "Ed25519",
      "key_id": "<same key_id as /certified/public-key>",
      "public_key": "https://example.invalid/certified/public-key",
      "signed_payload": "canonical JSON of answer_receipt: keys sorted recursively, no whitespace (see /certified/public-key)",
      "value": "<base64>"
    }
  }
}

Changes

No recorded changes to this operation across all 1 revision of this API.