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Duck Tax

by ducktax.com · remote · no sign-in to list tools · v1.0.0 · published by com.ducktax

Check micro-entity company accounts: raw figures in, validated balance sheet and deadlines out.

Deletes · 2Changes · 10

20 tools: 2 can delete or cancel things, 10 change things and 8 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http ducktax https://ducktax.com/api/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

20 tools

Deletes or cancels 2Claude Code: deny
  • delete_filingDelete one saved filing by id, permanently.No findings

    Why it is in this group

    • The name "delete_filing" says "delete": a word for removing or ending something.
    • The server marks it destructive (destructiveHint: true).
    Description, as the server wrote it
    Delete one saved filing by id, permanently. Confirm with the person before calling this; there is no undo and no trash.

    Annotations the server declares

    • title: Delete Filing
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: true
    • openWorldHint: true
  • untrack_company_deadlinesStop sending deadline reminders about a company.No findings

    Why it is in this group

    • The description's first verb is "stop": a word for a change.
    • The server marks it destructive (destructiveHint: true).
    Description, as the server wrote it
    Stop sending deadline reminders about a company. This mutes rather than forgets, which is the only thing that holds: a company implied by a saved filing would otherwise be re-added by the next scan. track_company_deadlines un-mutes it again.

    Annotations the server declares

    • title: Untrack Company Deadlines
    • readOnlyHint: false
    • destructiveHint: true
    • idempotentHint: true
    • openWorldHint: true
Changes things 10Claude Code: ask
  • categorise_transactionsCategorise bank-statement transaction descriptions into the fixed vocabulary this product maps to balance sheet lines (sales, software, owner-in, …).No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Categorise bank-statement transaction descriptions into the fixed vocabulary this product maps to balance sheet lines (sales, software, owner-in, …). Send description strings only, never amounts or dates. Sum the amounts per returned category yourself, then call totals_to_figures. One statement import is one quota unit; previously seen descriptions are answered from a shared cache free.

    Annotations the server declares

    • title: Categorise Transactions
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • check_accountsDerive a small-company balance sheet (micro-entity, in UK terms) from raw figures and validate it.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Derive a small-company balance sheet (micro-entity, in UK terms) from raw figures and validate it. Returns the derived sheet for the current and prior year, the figures the authority would reject (negatives where it wants a positive, share capital left at nil), and whether they are complete enough to hand to a filing product. It does NOT check that the sheet balances and cannot: retained earnings is derived as the balancing figure, so both sides always agree. Do not tell anybody their sheet was checked for internal consistency. Free and instant: call it after every change to the figures. All money in major units (pounds not pence, dollars not cents). Pass lastFiledAs from lookup_company and it also warns when figures showing activity are about to be filed dormant again.

    Annotations the server declares

    • title: Check Accounts
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • check_filing_extensionWhether a company can still apply to its registrar for more time to file, how many days are left to apply, and what being late costs if that window is missed.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Whether a company can still apply to its registrar for more time to file, how many days are left to apply, and what being late costs if that window is missed. This is usually the most useful thing to tell somebody who has just found a deadline: applying is free, takes about 15 minutes, and has to be done BEFORE the deadline it extends, so the option expires on the same day the penalty starts. Returns nextAction first. It PREPARES an application and can never submit one: the application is made by a director on the registrar’s own service, which this tool links to. It does not file accounts. Give a company number to read the deadline off the register (quota-charged, cached results free), or give the dates yourself and it costs nothing.

    Annotations the server declares

    • title: Check Filing Extension
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • dormant_figuresThe complete set of figures for a dormant company: share capital, the matching cash, and zeros everywhere else.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    The complete set of figures for a dormant company: share capital, the matching cash, and zeros everywhere else. The register says when the last accounts were filed dormant, and for those companies this collapses the whole form to one call. Amounts in major units.

    Annotations the server declares

    • title: Dormant Figures
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • draft_extension_reasonTurn a short factual account of what went wrong into the reason text for an application for more time to file accounts, framed in the terms the registrar actually applies.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Turn a short factual account of what went wrong into the reason text for an application for more time to file accounts, framed in the terms the registrar actually applies. It uses only the facts you give it: it will not invent circumstances, and where something is missing it leaves a bracketed placeholder rather than filling it in. The person must check every sentence before using it, because they are certifying it to the registrar. Ask them what happened, do not supply it yourself. This tool does not submit the application and does not file accounts. Quota-charged as an explanation; identical input is answered from cache free.

    Annotations the server declares

    • title: Draft Extension Reason
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • late_filing_penaltyWhat missing a Companies House accounts deadline costs.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    What missing a Companies House accounts deadline costs. Given the due date, returns days remaining or overdue, the penalty band already incurred, and what the next band costs, the number that makes someone act today. UK private companies only.

    Annotations the server declares

    • title: Late Filing Penalty
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • sample_accountsA real worked example: nil turnover, a director loan, a near-empty bank account, the simplest accounts the UK regime permits.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    A real worked example: nil turnover, a director loan, a near-empty bank account, the simplest accounts the UK regime permits. Use it to demonstrate check_accounts or as a template for a first-year company. Amounts in major units.

    Annotations the server declares

    • title: Sample Accounts
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • save_filingSave a set of figures to the user's account, or update a saved one by passing its id from list_saved_filings.No findings

    Why it is in this group

    • The name "save_filing" says "save": a word for a change.
    Description, as the server wrote it
    Save a set of figures to the user's account, or update a saved one by passing its id from list_saved_filings. Figures in major units. The filing is saved even when validation finds problems, because a work in progress is worth keeping, and the problems come back in the response so you can raise them.

    Annotations the server declares

    • title: Save Filing
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • totals_to_figuresTurn categorised bank-statement totals into balance sheet figures, applying the rules that stop an import lying: only income categories reach turnover, only expense categories reac…No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Turn categorised bank-statement totals into balance sheet figures, applying the rules that stop an import lying: only income categories reach turnover, only expense categories reach operating costs, and the owner topping up the account is never sales. Totals are signed major units per category code; get codes from categorise_transactions.

    Annotations the server declares

    • title: Totals To Figures
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • track_company_deadlinesWatch a company by its register number and get reminded before its filing deadlines.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    Watch a company by its register number and get reminded before its filing deadlines. Which channels are actually available depends on the server: the reply reports what will really be sent, and it can be nothing at all, so read it rather than assuming. No saved filing is needed: this is for the deadline itself, which matters months before any figures exist. Reminders go out on a ladder of days before the deadline (default 90, 60, 30, 14, 7, 1), and each one states the company, the deadline, the date, the days remaining and the penalty for missing it. Calling this again updates the settings and un-mutes a company that was untracked.

    Annotations the server declares

    • title: Track Company Deadlines
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
Only reads 8Claude Code: allow
  • explain_accountsA plain-English reading of a set of figures, written for a director who is not an accountant: what the derived balance sheet says about the company and anything that needs attentio…No findings

    Why it is in this group

    • The name "explain_accounts" says "explain": a word for reading.
    Description, as the server wrote it
    A plain-English reading of a set of figures, written for a director who is not an accountant: what the derived balance sheet says about the company and anything that needs attention before filing. Only the derived sheet is sent to the model, no company name or number. Quota-charged; identical figures are answered from cache free.

    Annotations the server declares

    • title: Explain Accounts
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • get_prior_year_figuresRead last year's figures out of the company's last filed accounts at Companies House, ready to drop into the *Prior fields of check_accounts or save_filing.No findings

    Why it is in this group

    • The name "get_prior_year_figures" says "get": a word for reading.
    Description, as the server wrote it
    Read last year's figures out of the company's last filed accounts at Companies House, ready to drop into the *Prior fields of check_accounts or save_filing. Saves typing seven numbers from a PDF and gets the comparatives exactly as filed. GB only, and only when the last accounts were filed digitally. Quota-charged; cached results are free.

    Annotations the server declares

    • title: Get Prior Year Figures
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • list_jurisdictionsThe countries this server knows about and what it can actually do in each: which have a real accounts engine, which registers can be searched or looked up, the currency, and the id…No findings

    Why it is in this group

    • The name "list_jurisdictions" says "list": a word for reading.
    Description, as the server wrote it
    The countries this server knows about and what it can actually do in each: which have a real accounts engine, which registers can be searched or looked up, the currency, and the identifiers each jurisdiction files under. Call this first when unsure.

    Annotations the server declares

    • title: List Jurisdictions
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • list_saved_filingsThe user's saved filings, most recently touched first, with every figure in major units.No findings

    Why it is in this group

    • The name "list_saved_filings" says "list": a word for reading.
    Description, as the server wrote it
    The user's saved filings, most recently touched first, with every figure in major units. This is the same list the website dashboard shows. Start here when asked about "my accounts" or "my company".

    Annotations the server declares

    • title: List Saved Filings
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • list_tracked_companiesEvery company this user gets deadline reminders about, including the ones implied by their saved filings.No findings

    Why it is in this group

    • The name "list_tracked_companies" says "list": a word for reading.
    Description, as the server wrote it
    Every company this user gets deadline reminders about, including the ones implied by their saved filings. Shows the next accounts deadline and days remaining where a register record is already cached. Free: this never contacts a register.

    Annotations the server declares

    • title: List Tracked Companies
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • lookup_companyLook a company up on its public register (Companies House for GB, ABN Lookup for AU) by its registered number.No findings

    Why it is in this group

    • The name "lookup_company" says "lookup": a word for reading.
    Description, as the server wrote it
    Look a company up on its public register (Companies House for GB, ABN Lookup for AU) by its registered number. Returns the full public record: name, status, registered office, officers, SIC codes, accounting period, plus both filing deadlines with days remaining and the late-filing penalty already incurred if overdue. Rate limited and quota-charged; cached results are free. Find the number first with search_companies.

    Annotations the server declares

    • title: Lookup Company
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • search_companiesFind a company by name on its public register and get back its registered number, status and address.No findings

    Why it is in this group

    • The name "search_companies" says "search": a word for reading.
    Description, as the server wrote it
    Find a company by name on its public register and get back its registered number, status and address. This is how you reach lookup_company when the person only knows the name. Free of the daily quota; lightly rate limited.

    Annotations the server declares

    • title: Search Companies
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • server_statusWhat this deployment can actually do right now: which integrations are configured, whether your token is valid, and how much of each daily quota you have left.No findings

    Why it is in this group

    • The name "server_status" says "status": a word for reading.
    Description, as the server wrote it
    What this deployment can actually do right now: which integrations are configured, whether your token is valid, and how much of each daily quota you have left. Call it when a tool refuses and you want to know whether the feature is off or used up.

    Annotations the server declares

    • title: Server Status
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http ducktax https://ducktax.com/api/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__ducktax__list_jurisdictions",
      "mcp__ducktax__lookup_company",
      "mcp__ducktax__search_companies",
      "mcp__ducktax__get_prior_year_figures",
      "mcp__ducktax__explain_accounts",
      "mcp__ducktax__list_saved_filings",
      "mcp__ducktax__list_tracked_companies",
      "mcp__ducktax__server_status"
    ],
    "ask": [
      "mcp__ducktax__check_accounts",
      "mcp__ducktax__dormant_figures",
      "mcp__ducktax__totals_to_figures",
      "mcp__ducktax__late_filing_penalty",
      "mcp__ducktax__sample_accounts",
      "mcp__ducktax__categorise_transactions",
      "mcp__ducktax__check_filing_extension",
      "mcp__ducktax__draft_extension_reason",
      "mcp__ducktax__save_filing",
      "mcp__ducktax__track_company_deadlines"
    ],
    "deny": [
      "mcp__ducktax__delete_filing",
      "mcp__ducktax__untrack_company_deadlines"
    ]
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as ducktax. Review it before you use it.