# S+ Money CIS Refund Calculator (remote · mcp.splusmoney.co.uk)

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

- Trust score: 70/100 (medium)
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `mcp.splusmoney.co.uk`: 70/100 (this document), [markdown](https://verifymcp.io/servers/uk-co-splusmoney-cis-refund-calculator/mcp.md), [page](https://verifymcp.io/servers/uk-co-splusmoney-cis-refund-calculator/mcp)

## Channel facts

- Endpoint: `https://mcp.splusmoney.co.uk/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `1.1.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 74/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one.
  - HTTPS is enforced; there's no plaintext access path.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC check failed: this domain isn't protected by DNSSEC.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 68/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (good).
  - Context-footprint check failed: tool/resource definitions use about 1330 tokens (~443/item across 3 items; 2 tools + 1 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 13/100
  - Stability observed for 4 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
- **Tool Safety**: 75/100
  - No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.
  - 0 of 1 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation; "estimate_cis_refund" implies "refund" and declares readOnlyHint instead, contradicting what its own name says it does.
  - An AI judge read all 4 captured unit(s) of tool text and found none that tries to manipulate the model reading it.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.
  - Supports UI / widget rendering.

## Install

### How do I install the S+ Money CIS Refund Calculator MCP server?

S+ Money CIS Refund Calculator is a hosted endpoint at https://mcp.splusmoney.co.uk/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http uk-co-splusmoney-cis-refund-calculator 'https://mcp.splusmoney.co.uk/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "uk-co-splusmoney-cis-refund-calculator": {
      "url": "https://mcp.splusmoney.co.uk/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "uk-co-splusmoney-cis-refund-calculator": {
      "type": "http",
      "url": "https://mcp.splusmoney.co.uk/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.uk-co-splusmoney-cis-refund-calculator]
url = "https://mcp.splusmoney.co.uk/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "uk-co-splusmoney-cis-refund-calculator": {
      "type": "remote",
      "url": "https://mcp.splusmoney.co.uk/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add uk-co-splusmoney-cis-refund-calculator --url 'https://mcp.splusmoney.co.uk/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  uk-co-splusmoney-cis-refund-calculator:
    url: "https://mcp.splusmoney.co.uk/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "uk-co-splusmoney-cis-refund-calculator": {
      "Transport": "http",
      "Url": "https://mcp.splusmoney.co.uk/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add uk-co-splusmoney-cis-refund-calculator -t streamable-http -u 'https://mcp.splusmoney.co.uk/mcp'
```

### Other

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

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-04 (score 70, +1)

No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-02 (score 69, +1)

- [functional improvement] Stability: unverified → 0.03

### 2026-11-01 (score 68)

First indexed and scored.

## MCP tools (2)

### `estimate_cis_refund` (~929 tokens)

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.

Input parameters:

- `accountancy_other_gbp` (number): Accountant fees, business bank charges, trade subscriptions, stationery. Default 0.
- `business_miles` (number): Business miles driven in own van/car (between sites, to merchants). Claimed at HMRC flat rates: 45p (2025-26) or 55p (2026-27 on) for the first 10,000; 25p after (35p from 2027-28, Budget 2026); 24p…
- `cis_deducted_gbp` (number): Total CIS deducted in the year, from the monthly CIS payment and deduction statements, GBP. If omitted it is worked out from cis_rate on the labour part.
- `cis_rate` (string): Deduction rate used when cis_deducted_gbp is not given: '20' (registered for CIS) or '30' (not registered). Default '20'.
- `gross_cis_income_gbp` (number, required): Total paid by contractors in the tax year BEFORE CIS deductions (labour plus any materials invoiced), GBP. Required.
- `insurance_gbp` (number): Public liability and tool insurance. Default 0.
- `materials_gbp` (number): Cost of materials the subcontractor bought and invoiced to contractors (CIS is not deducted from these; they are an expense). Default 0.
- `other_expenses_gbp` (number): Any other allowable business expenses. Default 0.
- `other_income_gbp` (number): Other taxable income in the same year from a PAYE job or pension (gross), GBP. Default 0.
- `parking_tolls_travel_gbp` (number): Parking, tolls, congestion/ULEZ charges for work trips, public transport and work-away accommodation. Default 0.
- `phone_internet_gbp` (number): Business share of phone and data. Default 0.
- `region` (string): Where the person lives for income tax: 'england_wales_ni' or 'scotland' (Scottish bands). Default england_wales_ni.
- `tax_paid_on_other_income_gbp` (number): Income tax already paid on that other income (from the P60/P45). Default 0.
- `tax_year` (string): UK tax year: '2025-26' (6 Apr 2025 to 5 Apr 2026, return due 31 Jan 2027), '2026-27' or '2027-28' (Budget 2026 rules; Scottish 2027-28 bands not yet set, 2026-27 ones used). Default '2025-26'.
- `tools_equipment_gbp` (number): Tools and equipment bought for work in the year. Default 0.
- `training_cards_gbp` (number): CSCS/CPCS cards and training that updates existing trade skills. Default 0.
- `vehicle` (string): Vehicle for business_miles. Default car_or_van.
- `vehicle_costs_gbp` (number): Business share of actual van/car costs, ONLY if not using mileage for that vehicle. Default 0.
- `workwear_ppe_gbp` (number): Protective clothing, PPE and branded workwear (not everyday clothes). Default 0.

### `get_cis_tax_rates` (~199 tokens)

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.

Input parameters:

- `region` (string): Income tax bands to show. Default england_wales_ni.
- `tax_year` (string): '2025-26', '2026-27' or '2027-28'. Default '2025-26'.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/uk-co-splusmoney-cis-refund-calculator/mcp#diagnostics

## Score history

- 2026-11-05: 70
- 2026-11-04: 70
- 2026-11-03: 69
- 2026-11-02: 69
- 2026-11-01: 68

## Common questions

### What is the S+ Money CIS Refund Calculator MCP server?

S+ Money CIS Refund Calculator is an MCP server listed in the public MCP registry as uk.co.splusmoney/cis-refund-calculator. Estimate a UK CIS construction subcontractor's tax refund for 2025-26 to 2027-28. Free, no sign-in. This page covers its hosted endpoint (https://mcp.splusmoney.co.uk/mcp).

### Is the S+ Money CIS Refund Calculator MCP server safe to use?

S+ Money CIS Refund Calculator scores 70 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the S+ Money CIS Refund Calculator MCP server expose?

S+ Money CIS Refund Calculator exposes 2 tools: estimate_cis_refund, get_cis_tax_rates. Their descriptions and schemas cost roughly 1,128 tokens of context every time the server is loaded.

### Does the S+ Money CIS Refund Calculator MCP server require authentication?

No. We connected to S+ Money CIS Refund Calculator without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.

### Is the S+ Money CIS Refund Calculator MCP server still maintained?

S+ Money CIS Refund Calculator is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

## Links

- Remote endpoint: https://mcp.splusmoney.co.uk/mcp
- Website: https://refund.splusmoney.co.uk/
- Changelog RSS feed: https://verifymcp.io/servers/uk-co-splusmoney-cis-refund-calculator/mcp.xml
- Changelog JSON feed: https://verifymcp.io/servers/uk-co-splusmoney-cis-refund-calculator/mcp.json
- HTML version of this page: https://verifymcp.io/servers/uk-co-splusmoney-cis-refund-calculator/mcp