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# Chase overdue Invoice Ninja invoices

> List overdue Invoice Ninja invoices, skip clients you emailed this week, resend a reminder and keep the oldest ones for a personal call.

Source: https://cotlet.dev/integrations/invoice-ninja-api-mcp-server/chase-overdue-invoices

Invoices pass their due date while you work on the next job, and you only notice when you open the Invoices list and scan the due dates against the calendar.

Cotlet does it in your own Invoice Ninja account with list\_invoices, get\_invoice and send\_invoice, called by your AI agent, an n8n workflow or a script.

[Sign up free](https://cotlet.dev/app/signup?app=invoice-ninja) [All Invoice Ninja tools](https://cotlet.dev/integrations/invoice-ninja-api-mcp-server.md)

Hosted · nothing to install or maintain

## Can Invoice Ninja do this on its own?

Invoice Ninja sends up to three automatic reminders, set under Settings > Templates & Reminders for every client or per client group, and lists auto payment reminders on Ninja Pro and above, not on Free (checked 14 Oct 2026). The reminders follow fixed days and templates. The REST API can list overdue invoices and email them, but it is Pro and above too, and Invoice Ninja has no official MCP server.

## How you do it in Invoice Ninja today

1. Open Invoices and look for invoices past their Due Date. An invoice with no Due Date is due immediately, so it never shows as late.
2. Click a row to open the overview panel, check the balance owing and the status, then open the Email History tab to see when the client last got an email.
3. Choose More Actions > Email Invoice to resend it to the contacts checked to receive it.
4. For a standing routine, set up to three reminders under Settings > Templates & Reminders, for example 3 days before the due date, 7 days overdue and 30 days overdue. Each reminder can add a flat fee or a percentage as a new line on the invoice.
5. Each client has a Send Reminders switch on the client record, so a client who was switched off there gets nothing from the schedule and the invoice waits until you look at it.

## How to chase overdue Invoice Ninja invoices

Prompt

```
List my overdue Invoice Ninja invoices. Skip any that were emailed in the last 7 days, resend the first reminder for the ones under 30 days late, and list the rest for me with the balance.
```

1. 01  
### Pull the overdue list  
Your agent calls list\_invoices with overdue set and pages through the cursor. It keeps invoices in Sent or Partial status with a balance above zero and never touches drafts or cancelled invoices.
2. 02  
### Check what the client already got  
get\_invoice returns the email log and linked payments for each one. An invoice emailed in the last 7 days, by you or by an automatic reminder from Settings, is skipped, so a client never gets two nudges in one week.
3. 03  
### Sort by how late  
Your prompt sets the lines, for example under 30 days gets a reminder and over 30 days goes to you. The agent shows days past due and the balance next to each invoice so the sorting is easy to audit.
4. 04  
### Resend with the right template  
send\_invoice emails the invoice again with the reminder template you named, and it asks for your OK per call until you switch confirmation off. Invoice Ninja adds a late fee only if your reminder settings define one; the agent never adds a fee itself.
5. 05  
### Hand over the rest  
Invoices past your cutoff are listed with client, balance and last email date, so the call you make has everything in one line.

### What you get back

Example data

```
Overdue invoices: 5, open balance 6,350.00 USD
Resent reminder 1 (3):
- INV-0038 Brightwave Ltd, 14 days, 1,800.00
- INV-0033 Kestrel Labs, 22 days, 2,100.00
- INV-0035 Orchard & Finch, 9 days, 300.00
Skipped (1): INV-0036 Northwind Studio, emailed 3 days ago
Left for you (1): INV-0031 Fenwick Ltd, 41 days, 950.00
```

### Other ways to ask

- Every Monday at 9, list overdue invoices and show me the drafts of the emails, but send nothing.
- Resend only invoices from clients who have paid us before and list first-time clients for me.
- Show me which overdue invoices have a Partial/Deposit amount past due while the full due date is still ahead.
- Cancel invoices that are over 90 days late and I marked as written off, after I confirm each one.

## What Invoice Ninja allows, and what to know first

- Invoice Ninja treats an invoice with no Due Date as due immediately, and an invoice with a Partial/Deposit has a separate due date for that amount.
- Invoice Ninja allows up to three reminders, and each can add a flat fee or a percentage of the outstanding balance as a new line on the invoice.
- Each client has a Send Reminders switch, and a group set up under Settings > Group Settings can carry its own reminder settings.
- Invoice Ninja lists auto payment reminders on Ninja Pro, Enterprise and Premium, and the Free plan does not include them.
- Cancelling a Sent, Partial or Paid invoice zeroes its balance and lowers the client balance, while linked payments stay linked.

send\_invoice asks for your OK by default. To run it weekly without you, switch confirmation off for that tool in your dashboard.

Sources: [Invoice Ninja Docs: Invoices](https://invoiceninja.github.io/docs/user-guide/invoices) · [Invoice Ninja Docs: Clients](https://invoiceninja.github.io/docs/user-guide/clients) · [Invoice Ninja Docs: Invoices API](https://invoiceninja.github.io/docs/developer-guide/api/invoices) · [Invoice Ninja: Pricing and plan comparison](https://invoiceninja.com/pricing-plans/)

## Call send\_invoice from a script

curl

```
curl -X POST https://cotlet.dev/api/v1/invoice-ninja/invoices/INV-0038 \
  -H "Authorization: Bearer $COTLET_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"template":"reminder1"}'
```

Example response

```
{
"invoice_number": "INV-0038",
"status": "sent",
"template": "reminder1",
"sent_to": [
"ap@brightwave.example"
],
"sent_at": "2026-10-14T09:00:00+02:00",
"balance": 1800
}
```

MCP: add https://cotlet.dev/mcp/v1 with the same key; the call is invoice\_ninja\_write → send\_invoice. Example data.

[Schedule it in n8n, Make, Zapier or cron](https://cotlet.dev/integrations/invoice-ninja-api-mcp-server.md#automations)

## Invoice Ninja tools this automation uses

__Cotlet Invoice Ninja tools used to chase overdue Invoice Ninja invoices__
| Tool | Parameters |
| -------------- | ------------------------------------------------------------------------- |
| list\_invoices | company, status, overdue, client\_id, date\_from, date\_to, limit, cursor |
| get\_invoice | company, invoice\_number |
| send\_invoice | company, invoice\_number, template |

[All 14 Invoice Ninja tools with descriptions](https://cotlet.dev/integrations/invoice-ninja-api-mcp-server.md#tools)

## Frequently asked questions

### Is it safe to connect Invoice Ninja to Cotlet?

Yes. You sign in to Invoice Ninja yourself, in your own Cloud Browser in the EU, and we never save your password. Your agents only get Invoice Ninja once you enable it, every background request is listed, and the browser profile is stored encrypted with AES-256-GCM, the cipher 1Password uses for its vaults. The AI model never sees a login, posts and messages wait for your OK, and Disable for agents cuts access in one click. Independent scanners grade cotlet.dev A+ on Qualys SSL Labs, securityheaders.com and Mozilla Observatory; live results are on https://cotlet.dev/security.

## More Invoice Ninja automations

- [Record bank transfers as Invoice Ninja payments](https://cotlet.dev/integrations/invoice-ninja-api-mcp-server/record-bank-transfers-as-payments.md)
- [Create Invoice Ninja invoices from a billing list](https://cotlet.dev/integrations/invoice-ninja-api-mcp-server/create-invoices-from-billing-list.md)
- [Invoice Ninja API and MCP server: every tool](https://cotlet.dev/integrations/invoice-ninja-api-mcp-server.md)
- [All use cases](https://cotlet.dev/use-cases.md)

## Give your agent access to Invoice Ninja.

Free 7-day trial with 2,000 credits, no card needed. Cotlet is independent and not affiliated with Invoice Ninja.

[Sign up free](https://cotlet.dev/app/signup?app=invoice-ninja)

---

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## For AI agents: sign your user up

Is your user asking you to sign them up for Cotlet? You can do it for them, no account or key needed.

1. Read the fields and their allowed values: GET https://cotlet.dev/api/v1/access-requests
2. Ask the user for each value: email, apps, what you will do with them. If they leave the password to you, generate a strong one and show it to them.
3. Show the user what you will send, then POST it as JSON to https://cotlet.dev/api/v1/access-requests.

One call creates the account and sends the access request; we email the user when access is granted.