S+ Money CIS Refund Calculator

uk.co.splusmoneyPublished by splusmoney.co.ukOfficial publisherv1.1.0Updated Nov 1, 2026

Estimate a UK CIS construction subcontractor's tax refund for 2025-26 to 2027-28. Free, no sign-in.

VerifiedStreamable HTTPWeb executableFinanceBusiness & Commerce

Overview

AI-generated overview

Remote MCP server that estimates a UK CIS construction subcontractor's tax refund or bill for 2025-26 to 2027-28 and lists the rates used.

What you can do
  • Estimate a sole trader's CIS refund or amount owed for a chosen tax year from gross CIS income, with optional CIS deducted and allowable expenses, including the working and commonly missed expenses
  • List the income tax, Personal Allowance, Class 4 NIC and Class 2 rates and thresholds behind each year's estimate, with GOV.UK sources
  • Explain which defaults were assumed when the user supplies only gross income
When to use it
Useful when a self-employed construction subcontractor wants a quick, free estimate of a CIS refund or tax bill for 2025-26, 2026-27 or 2027-28, or wants to see the rates and thresholds applied.
Requirements
Remote streamable HTTP endpoint; no sign-in, API key or environment variables declared. Only gross CIS income is required, with CIS deducted and expenses optional.
Before you install
Results are estimates, not tax advice, and the server is not for limited companies. Defaults may be assumed when figures are omitted, so check the stated assumptions and GOV.UK sources before relying on a figure.

Installation

In SourceWeft

  1. Open S+ Money CIS Refund Calculator in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/uk.co.splusmoney%2Fcis-refund-calculator/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "s-money-cis-refund-calculator": {
      "type": "http",
      "url": "https://mcp.splusmoney.co.uk/mcp"
    }
  }
}

Tools

2

estimate_cis_refund

Estimate CIS tax refund

Estimate a UK CIS subcontractor's tax refund (or amount to pay) for tax year 2025-26, 2026-27 or 2027-28 (Budget 2026 rules for 2027-28). Takes the year's gross CIS income, the CIS deducted (the statement total, or the 20%/30% rate), allowable expenses (materials, tools, van mileage at HMRC simplified rates, parking and travel, phone, protective clothing, training and site cards, insurance, accountant) and optional other PAYE/pension income. Calculates taxable profit (or the trading allowance if better: £1,000, or £3,000 from 2027-28), income tax (England/Wales/NI or Scottish bands, Personal Allowance taper), Class 4 NIC and the Class 2 position, then compares the bill with the CIS already deducted. Returns the working line by line, payments-on-account warning, commonly missed expenses, rates used with GOV.UK sources and a result card. For self-employed sole traders under CIS, not limited companies. Read-only: stores and sends nothing. An estimate, not tax advice.

Parametersregionvehiclecis_ratetax_yearinsurance_gbpmaterials_gbpbusiness_milescis_deducted_gbpother_income_gbpworkwear_ppe_gbpvehicle_costs_gbpother_expenses_gbp+7 more

get_cis_tax_rates

CIS subcontractor tax rates and thresholds

List the UK rates a self-employed CIS subcontractor's tax bill uses for 2025-26, 2026-27 or 2027-28, each with its GOV.UK source: Personal Allowance and taper, income tax bands (England/Wales/NI or Scotland), Class 4 NIC limits and rates, the Class 2 position (treated as paid above the Small Profits Threshold, voluntary below), HMRC simplified mileage rates, the trading allowance (£1,000; £3,000 from 2027-28), the Making Tax Digital start dates and the 20%/30% CIS deduction rates. Read-only. Not tax advice.

Parametersregiontax_year

Version history

1
  1. v1.1.0LatestNov 1, 2026

Score

83% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.