apply_late_fee
Manually apply the configured late fee to an invoice. Requires set_late_fee_settings(enabled=true) and a value > 0. Adds the fee as an adjustment, recalculates total + balance.
What apply_late_fee does
Performs the apply late fee operation against the organization's data.
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 apply_late_fee
Called by an MCP-compatible AI client (Claude Desktop, Claude Code, Cursor, Windsurf, Codex) when the user's prompt maps to this action.
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
apply_late_fee accepts 1 parameter — 1 required, 0 optional. The AI fills these in from your natural-language prompt; you never write them by hand.
| Parameter | Type | Required | Description |
|---|---|---|---|
| invoiceId | string | required | Invoice ID |
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 apply_late_fee call looks like:
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/call",
"params": {
"name": "apply_late_fee",
"arguments": {
"invoiceId": "inv_a1b2c3d4"
}
}
}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 apply_late_fee automatically.
“Apply the configured late fee to invoice IWP-000456.”
Use it in 30 seconds
Related tools
More from the Reminders & Late Fees category.
set_reminder_settingsConfigure automatic overdue-reminder settings (which days after due date, default subject/message, sendTime).
set_late_fee_settingsConfigure late-fee policy (flat or percentage, grace period, once or recurring).
send_reminderSend an overdue reminder email for a specific invoice. Requires the invoice has balanceDue > 0 and the customer has an email on file. Uses the org's SMTP config or fallback.
FAQ — apply_late_fee
What is apply_late_fee?▾
apply_late_fee is one of 102 tools in InvoiceCave's MCP server. Performs the apply late fee operation against the organization's data. 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 apply_late_fee?▾
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 apply_late_fee 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 apply_late_fee take?▾
apply_late_fee accepts 1 parameter — 1 required (invoiceId). The AI populates these from your plain-English prompt — see the parameter table and request example above.
Does apply_late_fee 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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