UK VAT Flat Rate Calculator — connector documentation

MCP endpoint: https://uk-vat-frs-calc.connectorbay.com/mcp
REST API: POST https://uk-vat-frs-calc.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://uk-vat-frs-calc.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-vat-frs-calc.connectorbay.com/health · Tool schemas: https://uk-vat-frs-calc.connectorbay.com/tools.json
Publisher: Unify Dynamics LLC · connectorbay.com/uk-vat-frs-calc · agent@connectorbay.com

What UK VAT Flat Rate Calculator is for

UK VAT Flat Rate Calculator works out what a small business would pay under the HMRC VAT Flat Rate Scheme and how that compares with standard VAT accounting. list_frs_categories and lookup_frs_rate return the flat rate percentage of the GOV.UK table for a trade category, choosing the dated row for catering, hotel and pub businesses (whose rates changed on 15 July 2020, 1 October 2021 and 1 April 2022) and showing the 1 percent first-year discount when a VAT registration date is supplied. compute_frs_payment applies the percentage to VAT-inclusive turnover. limited_cost_trader_test tests goods spend against 2 percent of turnover or GBP 1,000 a year and returns the 16.5 percent limited cost rate when it applies. compare_standard_vs_flat sets output minus input VAT against the flat rate result for a period, and joining_limit_check compares expected turnover with the GBP 150,000 joining figure. frs_reference returns every figure with its GOV.UK source, retrieval date and verification label. All arithmetic is exact decimal and local; nothing is stored, submitted or filed. General information only, not tax advice.

Ask your assistant things like:

"Which Flat Rate Scheme category and percentage fits a web design consultancy?"
"I registered for VAT in March: what flat rate do I pay in my first year as a management consultant?"
"We had GBP 24,000 of VAT-inclusive turnover this quarter as a consultancy: how much VAT is due on the flat rate?"
"I spend very little on goods: does the limited cost trader rate of 16.5% apply to me?"
"Would I pay less VAT this quarter on the flat rate or with standard accounting?"
"I run a cafe: what was the catering flat rate in summer 2021 and what is it now?"

What it does

list_frs_categories: List the Flat Rate Scheme trade categories of the GOV.UK table with the percentage in force on a date, optionally filtered by a search word.
lookup_frs_rate: Return the flat rate percentage of one trade category on a date, with the 1 percent first-year discount when a VAT registration date is given.
compute_frs_payment: Apply the flat rate percentage to VAT-inclusive turnover and return the VAT to pay for the period.
limited_cost_trader_test: Test goods spend against 2 percent of turnover or GBP 1,000 a year and return the 16.5 percent limited cost rate when the business is limited cost.
compare_standard_vs_flat: Compare output VAT minus input VAT under standard accounting with the flat rate result for the same period.
joining_limit_check: Compare expected VAT taxable turnover excluding VAT with the GBP 150,000 figure for joining the Flat Rate Scheme.
frs_reference: Return the Flat Rate Scheme figures and rules held here (joining figure, limited cost rate, first-year discount, dated rows) with sources and verification labels.

Data sources

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

What it is not

UK VAT Flat Rate Calculator 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 VAT Flat Rate Calculator 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

Look up & validate

list_frs_categories — List the Flat Rate Scheme trade categories of the GOV.UK table with the percentage in force on a date, optionally filtered by a search word. Use for "Which Flat Rate Scheme category and percentage fits a consultancy business?". Args: search, on_date.

lookup_frs_rate — Return the flat rate percentage of one trade category on a date, with the 1 percent first-year discount when a VAT registration date is given. Use for "What is the flat rate for management consultancy and does the first-year discount apply if I registered in March 2026?". Args: category, on_date, vat_registration_date.

Calculate

compute_frs_payment — Apply the flat rate percentage to VAT-inclusive turnover and return the VAT to pay for the period. Use for "My consultancy had GBP 24,000 of VAT-inclusive turnover this quarter: how much VAT do I pay on the Flat Rate Scheme?". Args: vat_inclusive_turnover, category, on_date, vat_registration_date, limited_cost_trader.

compare_standard_vs_flat — Compare output VAT minus input VAT under standard accounting with the flat rate result for the same period. Use for "With GBP 4,000 VAT charged and GBP 500 VAT on purchases, would standard VAT accounting or the flat rate cost less this quarter?". Args: vat_inclusive_turnover, output_vat, input_vat, category, on_date, vat_registration_date, limited_cost_trader, capital_asset_input_vat.

Reference & guides

limited_cost_trader_test — Test goods spend against 2 percent of turnover or GBP 1,000 a year and return the 16.5 percent limited cost rate when the business is limited cost. Use for "I spent GBP 300 on goods against GBP 24,000 of turnover: am I a limited cost business?". Args: goods_spend, vat_inclusive_turnover, period_months.

joining_limit_check — Compare expected VAT taxable turnover excluding VAT with the GBP 150,000 figure for joining the Flat Rate Scheme. Use for "I expect about GBP 120,000 of VAT taxable turnover next year: am I within the Flat Rate Scheme joining limit?". Args: expected_vat_taxable_turnover_excl_vat_next_12_months.

frs_reference — Return the Flat Rate Scheme figures and rules held here (joining figure, limited cost rate, first-year discount, dated rows) with sources and verification labels. Use for "Where do the Flat Rate Scheme percentages come from and how sure are they?". Args: on_date.

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-vat-frs-calc/support