UK MTD Deadlines — connector documentation

MCP endpoint: https://uk-mtd-deadlines.connectorbay.com/mcp
REST API: POST https://uk-mtd-deadlines.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://uk-mtd-deadlines.connectorbay.com/openapi.json
Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
Authentication: none required. An optional Authorization: Bearer <key> raises rate limits.
Health: https://uk-mtd-deadlines.connectorbay.com/health · Tool schemas: https://uk-mtd-deadlines.connectorbay.com/tools.json
Publisher: Unify Dynamics LLC · connectorbay.com/uk-mtd-deadlines · agent@connectorbay.com

What UK MTD Deadlines is for

UK MTD Deadlines answers the recurring Making Tax Digital date questions for sole traders, landlords and VAT-registered businesses using GOV.UK guidance. itsa_mandation_check maps qualifying income for 2024-25, 2025-26 and 2026-27 to the April 2026, 2027 or 2028 start date. quarterly_update_dates lists the four update periods and the 7 August, 7 November, 7 February and 7 May deadlines for standard or calendar quarters, and next_quarterly_deadline finds the next one from a date. penalty_points_status compares missed submissions with the 4-point threshold and the GBP 200 penalty, and late_payment_penalty works out the percentage penalties on tax paid late for 2026-27 and 2027-28. vat_return_due_date applies the one calendar month and 7 days rule to a VAT period end, and mtd_calendar_draft builds a dated list, with an .ics text, for the owner to import. It reads and calculates only: nothing is submitted. Exemptions, interest rates, VAT penalties and payment-on-account dates are not modelled.

Ask your assistant things like:

"My self-employment and property turnover was GBP 32,000 in 2025-26: when does Making Tax Digital for Income Tax start for me?"
"What are the quarterly update deadlines for 2026-27 and when is the next one?"
"I have missed 3 submission deadlines: how close am I to the GBP 200 penalty?"
"If GBP 4,000 of tax is 45 days late for 2026-27, what do the late payment penalties come to?"
"My VAT quarter ends on 30 September 2026: when must the return be filed and the payment reach HMRC?"
"Give me a draft calendar of my Making Tax Digital dates for 2026-27 that I can import."

What it does

itsa_mandation_check: Map qualifying income for 2024-25, 2025-26 and 2026-27 to the April 2026, 2027 or 2028 Making Tax Digital for Income Tax start date.
quarterly_update_dates: The four quarterly update periods and deadlines for a tax year (7 August, 7 November, 7 February, 7 May).
next_quarterly_deadline: From a date, the next quarterly update deadline and the days left.
penalty_points_status: Compare missed submissions with the 4-point threshold and the GBP 200 penalty.
late_payment_penalty: The percentage penalties on Making Tax Digital for Income Tax tax paid late for 2026-27 and 2027-28 onwards.
vat_return_due_date: VAT return and payment deadline: one calendar month and 7 days after the end of the VAT accounting period.
mtd_calendar_draft: A draft dated list, with .ics text, of the Making Tax Digital quarterly deadlines for a tax year and any VAT return deadlines you name.

Data sources

Reference data from official sources (gov.uk); every answer states its source, date and validity period.

What it is not

UK MTD Deadlines is independent; not affiliated with, endorsed by or operated by any government body, central bank, standards body or scheme operator. Names of rails, schemes and standards are used only to say what a tool works with. It is read-only: it never sends, pays, files or signs anything for you, and it never looks up private individuals.

Not advice. General information only, not legal, tax, accounting or payment advice. UK MTD Deadlines is an independent tool: it is not affiliated with, endorsed by or operated by any government body, central bank, standards body or scheme operator. Rates, thresholds and rules change; check the cited official source and confirm with a qualified professional before you rely on a result.

Built for: GB. Languages: English.

Tools

Reference & guides

itsa_mandation_check — Map qualifying income for 2024-25, 2025-26 and 2026-27 to the 6 April 2026, 2027 or 2028 Making Tax Digital for Income Tax start date. Use for "My turnover was GBP 32,000 in 2025-26: when does Making Tax Digital for Income Tax start for me?". Args: qualifying_income_2024_25, qualifying_income_2025_26, qualifying_income_2026_27, on_date.

quarterly_update_dates — The four Making Tax Digital quarterly update periods and deadlines for a tax year: 7 August, 7 November, 7 February and 7 May. Use for "What are the quarterly update deadlines for 2026-27?". Args: tax_year, quarter_basis.

next_quarterly_deadline — From a date, the next quarterly update deadline and the days left. Use for "When is my next Making Tax Digital quarterly update due?". Args: quarter_basis, on_date.

penalty_points_status — Compare missed submission deadlines with the 4-point threshold and the GBP 200 penalty. Use for "I have missed 3 submission deadlines: how close am I to the GBP 200 penalty?". Args: late_quarterly_updates_2027_28_onwards, late_final_declarations_or_returns, late_quarterly_updates_2026_27.

late_payment_penalty — The percentage penalties on Making Tax Digital for Income Tax tax paid late (3% for 2026-27, 4% for 2027-28) with the 10% annual charge. Use for "If GBP 4,000 of tax is 45 days late for 2026-27, what do the late payment penalties come to?". Args: tax_owed_at_day_15, days_late, tax_year, tax_owed_at_day_30, first_year.

vat_return_due_date — VAT return and payment deadline: one calendar month and 7 days after the end of the VAT accounting period. Use for "My VAT quarter ends on 30 September 2026: when must the return be filed and the payment reach HMRC?". Args: period_end, on_date.

mtd_calendar_draft — A draft dated list, with .ics text, of the Making Tax Digital quarterly deadlines for a tax year plus any VAT return deadlines you name. Use for "Give me a draft calendar of my Making Tax Digital dates for 2026-27 that I can import.". Args: tax_year, quarter_basis, vat_period_ends.

Conventions

Read-only. Every tool reads public data or computes; nothing is written anywhere and nothing about the user is stored.
Result envelope. ok: true with data, or ok: false with a structured error (bad_input, not_found, upstream_error). degraded lists optional sources that were unreachable.
Rate limits. Free tier 60 tool calls/minute and 300/day per user (keyed on the user identifier supplied by the host agent, else client IP); Pro keys raise this. Over-limit calls return HTTP 429 with Retry-After. initialize and tools/list are never counted.

Support

agent@connectorbay.com · connectorbay.com/uk-mtd-deadlines/support