add_tax_rate
Add a new tax rate to the org's tax rate list. Setting isDefault=true unsets any prior default.
What add_tax_rate does
Adds or removes a sub-resource attached to a parent record (e.g. line items on an invoice, payment methods on a customer).
This tool is part of InvoiceCave's open MCP server — the most MCP-complete invoicing platform on the market with 102 tools covering invoices, customers, quotes, expenses, payments, recurring schedules, accounting, and reports. Every tool is callable from any MCP-compatible AI client without writing a single line of integration code.
How an AI uses add_tax_rate
Useful when the AI needs to incrementally build up a record — "add another hour of consulting to the existing invoice" — without rewriting the whole parent. All changes are reflected in the next list_* or get_* call.
You don't call this tool directly — you ask the AI in plain English and the MCP client decides which tool to invoke based on your request. The example prompts below were lifted from real Claude Desktop sessions, so you can use them verbatim or adapt them to your data.
Parameters
add_tax_rate accepts 4 parameters — 2 required, 2 optional. The AI fills these in from your natural-language prompt; you never write them by hand.
| Parameter | Type | Required | Description |
|---|---|---|---|
| name | string | required | Display name (e.g. "VAT 20%", "GST") |
| rate | number | required | Percentage rate (e.g. 20 for 20%) |
| isDefault | boolean | optional | Set as the default tax rate |
| isCompound | boolean | optional | Whether this tax compounds on top of others |
Request example
Under the hood, your AI client sends a JSON-RPC 2.0 tools/call request to InvoiceCave's MCP endpoint at https://www.invoicecave.com/api/mcp/mcp. Here's what a add_tax_rate call looks like:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "add_tax_rate",
"arguments": {
"name": "Acme Corp",
"rate": 10,
"isDefault": true,
"isCompound": true
}
}
}You won't write this yourself — it's shown so developers can see exactly what the MCP client generates. The arguments object maps 1:1 to the parameters above. Authentication is handled by the Authorization: Bearer header with your API key.
Example AI prompts
Type any of these into Claude Desktop, Claude Code, or Cursor — InvoiceCave's MCP server will route them to add_tax_rate automatically.
“Run the "add tax rate" action for me.”
Use it in 30 seconds
Related tools
More from the Tax Rates category.
FAQ — add_tax_rate
What is add_tax_rate?▾
add_tax_rate is one of 102 tools in InvoiceCave's MCP server. Adds or removes a sub-resource attached to a parent record (e.g. line items on an invoice, payment methods on a customer). It's invoked automatically when an AI client like Claude or Cursor decides the user's request maps to this action.
Which AI clients can call add_tax_rate?▾
Any MCP-compatible client. We've tested it with Claude Desktop, Claude Code, Cursor, Windsurf, and Codex. The MCP protocol is open, so any AI tool that speaks MCP can call this endpoint with a valid InvoiceCave API key.
Is calling add_tax_rate secure?▾
Yes. Every call is authenticated by the API key you mint in the dashboard, scoped to a single organization, rate-limited per key, and recorded in the audit log with source='mcp'. Sensitive fields (SMTP passwords, encryption keys) are never returned to the AI client.
What parameters does add_tax_rate take?▾
add_tax_rate accepts 4 parameters — 2 required (name, rate) and 2 optional. The AI populates these from your plain-English prompt — see the parameter table and request example above.
Does add_tax_rate count against any quota?▾
MCP tool calls are unmetered on the free plan up to a generous monthly limit. Once you connect Stripe and start charging your customers, every call still counts against the same per-key rate limit but doesn't add to your bill.
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