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The mapTax authorityTaxpayer Services
E-filing & pre-filled returns
partly covered · 28 open projects
Filing portals, pre-filled returns, filing APIs for software, identity and sign-in.
The honest read
The code of the IRS's Direct File and of HMRC's filing services (VAT, Pillar Two, Digital Services Tax, Income Tax, country-by-country reporting, CRS/FATCA, customs declarations and transit) is public, Norway's and Hungary's tax administrations publish their filing APIs, validators and samples, Denmark's its VAT sample clients, and community SDKs wrap the German and Norwegian filing APIs. Pre-filling engines: none in the list.
A draft: not yet reviewed by a tax specialist.
Start with
An authority's own filing API, and a community SDK for Germany's ELSTER library: the two ways filing code becomes public.
Its 28 projects
| Project | Kind | Jurisdiction | Last update | Stars |
|---|---|---|---|---|
| HMRC VAT APIHMRC's Making Tax Digital VAT API: obligations, returns, payments, liabilities and penalties. | APIs | UK | Aug 2026 | 73 |
| eric-rsRust bindings and SDK for ERiC, the ELSTER library for submitting German tax filings. | APIs | DE | Sep 2026 | 34 |
| elster-mcp-serverMCP server for the German ELSTER portal: submits VAT pre-returns and prepares income tax filings. | MCP | DE | Jul 2026 | 13 |
| HMRC CDS FinancialsHMRC's CDS financial services: duty deferment statements, cash and guarantee accounts. | APIs | UK | Oct 2026 | — |
| HMRC Country-by-country reportingHMRC's service for uploading country-by-country reports as XML files, with its backend and file validation. | APIs | UK | Jul 2026 | — |
| HMRC CRS/FATCA reporting serviceHMRC's CRS and FATCA reporting service: registration, institution management and report upload. | APIs | UK | Oct 2026 | — |
| HMRC Customs Declaration Service APIsHMRC's Customs Declaration Service APIs: submit, amend and cancel declarations, upload documents. | APIs | UK | Sep 2026 | — |
| HMRC Customs Exports Declaration ServiceHMRC's Customs Exports Declaration Service: trader frontend, declaration backend and the movements service. | APIs | UK | Oct 2026 | — |
| HMRC customs inventory linking APIsHMRC's inventory linking APIs for import declarations and for export consignment consolidation and movement. | APIs | UK | Sep 2026 | — |
| HMRC Digital Platform Reporting serviceHMRC's Digital Platform Reporting service (DAC7 rules): registration, operators, seller-data XML filing. | APIs | UK | Oct 2026 | — |
| HMRC Digital Services TaxHMRC's Digital Services Tax service: registration and returns, with a frontend and test stubs. | APIs | UK | Oct 2026 | — |
| HMRC EORI servicesHMRC's EORI services: an API that checks a GB EORI number and returns trader details, with its backend. | APIs | UK | Sep 2026 | — |
| HMRC Import Control System (ICS2)HMRC's import control services: entry summary declaration store, ICS2 WSDL schemas, safety and security guide. | APIs | UK | Sep 2026 | — |
| HMRC Income Tax (MTD) servicesHMRC service that collects dividend, interest, Gift Aid, CIS, employment and pension data for Income Tax MTD. | APIs | UK | Jun 2026 | — |
| HMRC Mandatory Disclosure Rules serviceHMRC's mandatory disclosure rules (MDR) service: credentials and subscription details, XML checks, submission. | APIs | UK | Oct 2026 | — |
| HMRC New Computerised Transit System (NCTS)HMRC's transit services: traders API, NCTS validator and converter, movement store, documents, guarantees. | APIs | UK | Oct 2026 | — |
| HMRC Pillar 2 servicesHMRC's Pillar Two service code: the submission API, the registration frontend and backend, and test stubs. | APIs | UK | Oct 2026 | — |
| HMRC Senior Accounting Officer serviceHMRC's Senior Accounting Officer service: registration, hub, notification and certificate submission. | APIs | UK | Oct 2026 | — |
| HMRC submission trackerService that tracks the status of forms and submissions sent to HMRC. | APIs | UK | Sep 2026 | — |
| mcp-skatteetatenMCP server for the Norwegian Tax Administration's APIs, with Maskinporten sign-in.Licence unknown | MCP | NO | Mar 2026 | — |
| NAV DCC-APISchemas and Java models of the Hungarian tax authority's DAC9 (GloBE return), DAC8 and CARF exchange API. | APIs | HU · EU | Oct 2026 | — |
| NAV eVATPublic repository of Hungary's eVAT system: M2M interface docs, schemas and example XML for the VAT return.Licence unknown | APIs | HU | Sep 2026 | 34 |
| NAV M2MSchemas, example XML and Swagger specifications for machine-to-machine form submission to Hungary's NAV. | APIs | HU | Oct 2026 | 33 |
| NAV M2M XML editorJava desktop app for NAV M2M forms: XSD-based editing, validation and multi-form processing. | Automations | HU | Oct 2026 | — |
| Skatteetaten mva-meldingenImplementation guide and validation material for the Norwegian VAT return (mva-melding) API. | APIs | NO | Nov 2025 | 15 |
| Skatteetaten skattemeldingenCode and specs for filing the Norwegian tax return: APIs, a validation service, XSDs and a Kotlin calculation. | APIs | NO | Oct 2026 | 47 |
| Skatteetaten suppleringsskattThe Norwegian Tax Administration's notes on GloBE Information Return filing: XML format, XSD check, test file.Licence unknown | APIs | NO | Oct 2025 | — |
| Skattestyrelsen RSU B2B sample clientsDanish Tax Agency sample Java and .NET clients that submit VAT returns and fetch periods and receipts.Licence unknown | APIs | DK | Sep 2026 | — |
Every project here is maintained and serves a tax authority. See the team's projects in the list.
On Learn
- Country-by-country report (CbCR)Glossary term
- GloBE Information Return (GIR)Glossary term