Britixo CRMBritixo CRMEnterprise Help Centre
Ctrl K
MTD - HMRC Compliant Module · How-to guide

Prepare, review and submit the final declaration

Freeze the final declaration instruction against the HMRC calculation ID, collect required approvals and submit only when the Production gate is enabled. The guide then takes you through the correct route, the checks to complete before making changes, the workflow in order, and the evidence to review afterwards.

Audience: Income Tax taxpayers, accountants and authorised agentsModule v1.0.0Code-backed
Jump to steps
Where to goTax Centre → Income Tax / Approvals
Before you startRequired access: Prepare/review/approve/submit as appropriate; final declaration additionally requires the Production gate. Work on the correct tenant and taxpayer profile. Reconcile the underlying Accounting & Bookkeeping records before relying on prepared tax totals.

What you’ll accomplish

Freeze the final declaration instruction against the HMRC calculation ID, collect required approvals and submit only when the Production gate is enabled. The MTD module stores tax profiles, HMRC authority, obligations, frozen filing snapshots, approvals and audit evidence, while Accounting remains the primary financial record system.

Follow these steps

  1. Verify the final-declaration Production gate is enabled only after approval/testing and exact current declaration text is configured.
  2. Complete all required business updates and other Self Assessment information for the tax year.
  3. Trigger/retrieve the HMRC calculation and obtain the calculation ID.
  4. Prepare the final declaration snapshot using the tax year, calculation ID and initial/amendment mode.
  5. Check the taxpayer declaration frozen into the snapshot; for agent filing also review the configured agent declaration.
  6. Record valid client approval and, for agent final filing, valid agent approval against the same snapshot hash.
  7. Submit the exact approved final declaration instruction to HMRC and retain the resulting audit/submission evidence.

Checks before you continue

Taxpayer profileAlways verify the correct profile, tax regime and masked identifiers before preparing or submitting.
Tenant contextTax records, HMRC authority and audit history must stay inside the current Britixo tenant/runtime.
Accounting sourceSource tax figures must come through the verified Accounting digital-link adapter with transaction lineage.
Approval stateThe exact frozen snapshot must carry the approvals required by its filing mode before HMRC submission.

Technical basis for this guidance

This guide was checked against libraries/Mtd_hmrc_income_tax_service.php; libraries/Mtd_approval_service.php; views/admin/income_tax.php; views/admin/review.php. The user instructions describe only behaviour exposed or enforced by the supplied module. Internal secrets, encrypted token values and database identifiers are intentionally not shown to ordinary users.

Compliance and operational boundaries

  • Britixo Accounting & Bookkeeping remains the authoritative ledger; the MTD module is a tax preparation/submission layer.
  • Government Gateway usernames and passwords must never be entered into or stored by Britixo.
  • A tax filing must not proceed when transaction-level digital lineage cannot be proven.
  • Income Tax final declaration is disabled by default and must remain disabled until the Production gate and exact current declaration wording are satisfied.
Accounting interlinkFor transaction creation, tax mappings, banking, reconciliation, journals, reports and source-document corrections, use the Accounting & Bookkeeping Help Centre. Correct the bookkeeping source first; do not type replacement totals into MTD merely to clear an error.
Accounting & BookkeepingOpen related guidanceAll MTD - HMRC Compliant guidesOpen related guidance