0s and 1s CIS calculators
Free UK CIS calculators: deductions, deadlines, late penalties, gross payment test, verification.
Installation
Ajoutez ceci à la configuration MCP de votre client (Claude Desktop : claude_desktop_config.json ; Cursor : .cursor/mcp.json ; VS Code et les autres utilisent la même forme « mcpServers »).
claude mcp add --transport http 0s-and-1s-cis-calculators 'https://0sand1s.co.uk/mcp'{
"mcpServers": {
"0s-and-1s-cis-calculators": {
"type": "http",
"url": "https://0sand1s.co.uk/mcp"
}
}
}Documentation
Tirée du README du projet sur GitHub, actualisée chaque semaine. Les liens ouvrent GitHub.
0s and 1s CIS MCP server
Free calculators for the UK Construction Industry Scheme (CIS), as a remote MCP server and a JSON API. For contractors who pay subcontractors, and the bookkeepers who do it for them.
- MCP server:
https://0sand1s.co.uk/mcp(Streamable HTTP, no sign-in) - REST API:
https://0sand1s.co.uk/api/v1(OpenAPI) - Docs: https://0sand1s.co.uk/developers
No key and no account. Nothing you send is stored. Up to 60 requests a minute from one address, the API and the MCP server together.
Tools
| Tool | What it works out |
|---|---|
cis_deduction | The CIS deduction on a payment: gross, VAT and materials in, deduction and net out, with the working |
cis_gross_up | The gross to pay so the subcontractor receives a given net |
cis_tax_month | The tax month a date falls in, the return due date (19th) and the electronic payment date (22nd, moved for weekends and bank holidays) |
cis_late_penalties | What a late CIS300 or nil return costs, stage by stage |
cis_gross_payment_turnover_test | Whether a business meets the turnover test for gross payment status |
cis_needs_verification | Whether a subcontractor must be verified with HMRC before a payment |
cis_nil_return_check | Whether a nil return is due for a tax month |
Money goes in as pounds ("1,200.00") and comes back as pence and pounds. Dates are YYYY-MM-DD. Every answer lists the GOV.UK and legislation.gov.uk pages it follows. Answers follow the published rules; they are not tax advice and do not come from HMRC.
Connect
Claude (claude.ai and the desktop app): Customize, Connectors, Add custom connector, then name it 0s and 1s with the URL https://0sand1s.co.uk/mcp.
Claude Code:
claude mcp add --transport http 0sand1s https://0sand1s.co.uk/mcpCursor (~/.cursor/mcp.json):
{ "mcpServers": { "0sand1s": { "url": "https://0sand1s.co.uk/mcp" } } }VS Code (.vscode/mcp.json):
{ "servers": { "0sand1s": { "type": "http", "url": "https://0sand1s.co.uk/mcp" } } }Try the API
curl "https://0sand1s.co.uk/api/v1/deduction?gross=1200&vat=200&materials=300&rate=20"About this repository
This repository holds the listing for the official MCP registry (server.json, name uk.co.0sand1s/cis) and this README. The server is hosted by 0s and 1s, CIS filing software for contractors. Questions: support@0sand1s.co.uk.
Questions fréquentes
Qu'est-ce que 0s and 1s CIS calculators ?
Free UK CIS calculators: deductions, deadlines, late penalties, gross payment test, verification.
Comment installer 0s and 1s CIS calculators ?
Il fonctionne comme serveur distant. Dans Claude Code : claude mcp add --transport http 0s-and-1s-cis-calculators 'https://0sand1s.co.uk/mcp'. Pour les autres clients, collez la configuration JSON de cette page dans leurs réglages MCP.
Faut-il une clé API pour 0s and 1s CIS calculators ?
Son entrée au registre n'indique aucune clé ni secret obligatoire. Certaines fonctions peuvent tout de même demander un compte auprès du service auquel il se connecte.
0s and 1s CIS calculators est-il open source ?
Oui. Son code est sur GitHub sous licence MIT.
Qui maintient 0s and 1s CIS calculators ?
Il est publié par 0sand1s-uk. AI.tn le référence sans le maintenir ni le recommander.
Issu du registre MCP officiel. Être listé n'est pas une recommandation : vérifiez le code et les permissions d'un serveur avant de lui donner accès à vos données.