{
  "id": "uk-tax",
  "title": "UK VAT and tax basics",
  "summary": "UK VAT by the rate in force on the date of supply: add, remove, the nine-box return and the flat rate scheme, plus the tax year and HMRC identifiers.",
  "synonyms": [
    "vat",
    "value added tax",
    "hmrc",
    "uk tax",
    "tax year",
    "vat return",
    "making tax digital",
    "sales tax uk"
  ],
  "apps": [
    "any UK app that invoices or records VAT"
  ],
  "language": "python",
  "includes": [],
  "includedBy": [
    "accounting",
    "construction",
    "ecommerce",
    "energy",
    "hospitality",
    "investments",
    "invoicing",
    "legal",
    "professional-services",
    "subscriptions",
    "telecoms"
  ],
  "caveats": [
    "Calculates tax from published rules; it is not tax advice. Have an accountant check how the app uses it before anyone files a return."
  ],
  "sections": [
    {
      "key": "vat",
      "title": "VAT",
      "purpose": "Work out VAT from the dated rates HMRC publishes.",
      "from": "uk-tax",
      "members": [
        {
          "id": "finance.tax.vat-rate",
          "tier": "core",
          "why": "The VAT rate in force for a jurisdiction, category and date; the others look it up.",
          "section": "vat",
          "from": "uk-tax",
          "version": "1.2.2",
          "summary": "Look up the VAT rate in force for a jurisdiction, category and date.",
          "status": "unreviewed",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "vatRate"
          ],
          "signatures": [
            "def vat_rate(jurisdiction: str, category: str, on_date: str) -> VatRate"
          ],
          "reference": "from fune.finance.tax.vat_rate import vat_rate  # finance.tax.vat-rate@^1",
          "url": "http://www.functionalweave.com/functions/finance.tax.vat-rate"
        },
        {
          "id": "finance.tax.add-vat",
          "tier": "core",
          "why": "Net to gross: VAT on a net amount at the rate on the date of supply.",
          "section": "vat",
          "from": "uk-tax",
          "version": "1.0.1",
          "summary": "Add VAT to a net amount using the rate in force on the date of supply.",
          "status": "unreviewed",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "addVat"
          ],
          "signatures": [
            "def add_vat(net: Money, jurisdiction: str, category: str, on_date: str) -> VatBreakdown"
          ],
          "reference": "from fune.finance.tax.add_vat import add_vat  # finance.tax.add-vat@^1",
          "url": "http://www.functionalweave.com/functions/finance.tax.add-vat"
        },
        {
          "id": "finance.tax.remove-vat",
          "tier": "core",
          "why": "Gross to net: the VAT already inside a VAT-inclusive price.",
          "section": "vat",
          "from": "uk-tax",
          "version": "1.0.2",
          "summary": "Extract the VAT already included in a gross amount, using the rate in force on the date of supply.",
          "status": "unreviewed",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "removeVat"
          ],
          "signatures": [
            "def remove_vat(gross: Money, jurisdiction: str, category: str, on_date: str) -> VatBreakdown"
          ],
          "reference": "from fune.finance.tax.remove_vat import remove_vat  # finance.tax.remove-vat@^1",
          "url": "http://www.functionalweave.com/functions/finance.tax.remove-vat"
        },
        {
          "id": "finance.tax.vat-return",
          "tier": "optional",
          "why": "The nine-box VAT return totals for a period from categorised sales and purchases.",
          "section": "vat",
          "from": "uk-tax",
          "version": "1.0.1",
          "summary": "UK nine-box VAT return totals for a period from categorised sales and purchases (VAT Notice 700/12).",
          "status": "unreviewed",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "vatReturn"
          ],
          "signatures": [
            "def vat_return(transactions: Sequence[VatTransaction], period_start: str, period_end: str) -> VatReturn"
          ],
          "reference": "from fune.finance.tax.vat_return import vat_return  # finance.tax.vat-return@^1",
          "url": "http://www.functionalweave.com/functions/finance.tax.vat-return"
        },
        {
          "id": "finance.tax.vat-flat-rate",
          "tier": "optional",
          "why": "VAT due under the Flat Rate Scheme by business sector, for small businesses on it.",
          "section": "vat",
          "from": "uk-tax",
          "version": "1.0.1",
          "summary": "UK VAT Flat Rate Scheme: VAT due on gross turnover at the sector's dated rate, limited cost rate and first-year 1% off.",
          "status": "unreviewed",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "flatRateVat"
          ],
          "signatures": [
            "def flat_rate_vat(turnover: Money, sector: str, limited_cost_business: bool, registration_date: Optional[str], supply_date: str) -> FlatRateVat"
          ],
          "reference": "from fune.finance.tax.vat_flat_rate import flat_rate_vat  # finance.tax.vat-flat-rate@^1",
          "url": "http://www.functionalweave.com/functions/finance.tax.vat-flat-rate"
        }
      ],
      "gaps": []
    },
    {
      "key": "tax-year",
      "title": "Tax periods",
      "purpose": "Put dates into the UK periods tax is worked out over.",
      "from": "uk-tax",
      "members": [
        {
          "id": "dates.uk-tax-year",
          "tier": "core",
          "why": "Which UK tax year (6 April to 5 April) a date falls in.",
          "section": "tax-year",
          "from": "uk-tax",
          "version": "1.0.0",
          "summary": "The UK personal tax year containing a date: 6 April to 5 April, with HMRC's label.",
          "status": "stable",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "ukTaxYear"
          ],
          "signatures": [
            "def uk_tax_year(iso: str) -> UkTaxYear"
          ],
          "reference": "from fune.dates.uk_tax_year import uk_tax_year  # dates.uk-tax-year@^1",
          "url": "http://www.functionalweave.com/functions/dates.uk-tax-year"
        }
      ],
      "gaps": []
    },
    {
      "key": "identifiers",
      "title": "Tax identifiers",
      "purpose": "Check the numbers HMRC and Companies House issue before storing them.",
      "from": "uk-tax",
      "members": [
        {
          "id": "validation.uk-vat-number",
          "tier": "core",
          "why": "Checks a UK VAT registration number's checksum.",
          "section": "identifiers",
          "from": "uk-tax",
          "version": "1.0.0",
          "summary": "Check a UK VAT registration number against HMRC's mod-97 checksum, including the post-2010 9755 variant.",
          "status": "stable",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "isUkVatNumber"
          ],
          "signatures": [
            "def is_uk_vat_number(value: str) -> bool"
          ],
          "reference": "from fune.validation.uk_vat_number import is_uk_vat_number  # validation.uk-vat-number@^1",
          "url": "http://www.functionalweave.com/functions/validation.uk-vat-number"
        },
        {
          "id": "validation.uk-utr",
          "tier": "optional",
          "why": "Checks a Unique Taxpayer Reference's check digit.",
          "section": "identifiers",
          "from": "uk-tax",
          "version": "2.0.1",
          "summary": "Check an HMRC Unique Taxpayer Reference's modulus 11 check digit, accepting the K and spacing people type.",
          "status": "stable",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "validateUkUtr"
          ],
          "signatures": [
            "def validate_uk_utr(value: str) -> UkUtr"
          ],
          "reference": "from fune.validation.uk_utr import validate_uk_utr  # validation.uk-utr@^2",
          "url": "http://www.functionalweave.com/functions/validation.uk-utr"
        },
        {
          "id": "validation.uk-company-number",
          "tier": "optional",
          "why": "Checks and pads a Companies House company number.",
          "section": "identifiers",
          "from": "uk-tax",
          "version": "2.0.1",
          "summary": "Check a Companies House company number's format and prefix (SC, NI, OC, LP...) and zero-pad it to eight characters.",
          "status": "stable",
          "license": "NOASSERTION",
          "languages": [
            "typescript",
            "python",
            "rust"
          ],
          "available": true,
          "group": false,
          "functions": [
            "validateUkCompanyNumber"
          ],
          "signatures": [
            "def validate_uk_company_number(value: str) -> UkCompanyNumber"
          ],
          "reference": "from fune.validation.uk_company_number import validate_uk_company_number  # validation.uk-company-number@^2",
          "url": "http://www.functionalweave.com/functions/validation.uk-company-number"
        }
      ],
      "gaps": []
    }
  ],
  "gaps": [
    {
      "key": "mtd-submission",
      "text": "Making Tax Digital: submitting the return to HMRC's VAT API (OAuth, fraud-prevention headers, obligations) is yours; caps gives the nine boxes.",
      "section": null,
      "from": "uk-tax"
    },
    {
      "key": "corporation-tax",
      "text": "Corporation tax and self-assessment income tax computations are not in caps.",
      "section": null,
      "from": "uk-tax"
    },
    {
      "key": "vat-number-lookup",
      "text": "Checking that a VAT number is registered (HMRC's lookup API) is network work; caps checks the checksum only.",
      "section": null,
      "from": "uk-tax"
    }
  ],
  "counts": {
    "members": 9,
    "core": 5,
    "optional": 4,
    "unreviewed": 5,
    "deprecated": [],
    "unavailable": [],
    "missing": [],
    "gaps": 3
  },
  "warnings": [
    "3 core capabilities are unreviewed - they pass their tests but await an expert's sign-off; tell the user before relying on them, and never use one silently for tax, payroll, legal, clinical or other regulated rules: finance.tax.vat-rate, finance.tax.add-vat, finance.tax.remove-vat",
    "2 optional capabilities are unreviewed too: finance.tax.vat-return, finance.tax.vat-flat-rate",
    "Calculates tax from published rules; it is not tax advice. Have an accountant check how the app uses it before anyone files a return."
  ],
  "url": "http://www.functionalweave.com/suites/uk-tax",
  "owner": null
}