Your clients owe you money.
Dun gets it back.

Automated payment reminder emails that escalate from a friendly nudge to a formal demand letter. You set it up once. Dun runs in the background forever.

One-time purchase. No subscription. No cloud. No account. Windows only.

[App screenshot]

Seven stages.
Friendly to formal.

Each stage sends a firmer email. You control the timing. Paid invoices stop immediately.

01Pre-due reminder3 days before
02Friendly follow-up3 days overdue
03Firm reminder7 days overdue
04Formal notice14 days overdue
05Demand for payment21 days overdue
06Final demand + PDF letter30 days overdue
07Small claims reference60 days overdue

What Dun does.

Emails

Sends from your email address

Connects to Gmail, Outlook, or any SMTP. Replies go directly to you. Clients never know it is automated.

Documents

Professional PDF invoices and letters

Export invoices with your letterhead, line items, tax, and payment methods. Generate custom letters at any tone.

Billing

Services, expenses, and tax

Separate line items for services and expenses. Gross Receipts Tax with independent toggles. Late fees on post-tax totals.

Flexible

Import invoices you already have

Use QuickBooks or FreshBooks? Drag-drop your existing PDF. Dun attaches it to every reminder email automatically.

Legal

PDF demand letters at stage 5+

Professional demand letter automatically generated and attached. Includes invoice details, payment history, and next steps warning.

Records

Full audit trail

Every email logged with timestamps and delivery status. Filter by date or invoice. Export as CSV or JSON.

Privacy

100% local. No cloud. No telemetry.

All data stays on your computer. No account required. No tracking. Your invoices and client data never leave your machine. The app works offline after the one-time license activation.

Set up in five minutes.

1

Add your invoices

Enter client, amount, due date. Or drop a PDF you already have. Reference numbers auto-increment. Client names auto-complete from previous invoices.

2

Connect your email

One-click setup for Gmail, Outlook, or Yahoo. Dun sends from your address so replies come to you and clients see your name.

3

Walk away

Dun runs in the background and escalates automatically. Mark invoices paid when money arrives. Dun stops immediately. That is the entire workflow.

$29. Once. Done.

Competitors charge $29 to $115 every month for less.

Chaser / Paidnice

$49-69
per month, every month
  • Requires Xero or QuickBooks
  • Cloud-only, enterprise-focused
  • Monthly subscription

Dun

$29
one-time, yours forever
  • 7-stage automated escalation
  • PDF invoices, letters, demand letters
  • Services, expenses, tax toggles
  • Import existing invoice PDFs
  • Full audit trail with CSV/JSON export
  • No cloud, no account, no subscription
  • Free updates for all 1.x versions
  • 30-day money-back guarantee

FreshBooks / QuickBooks

$19-115
per month, every month
  • 3 reminder emails maximum
  • No escalation logic
  • Full accounting suite you do not need

Stop writing uncomfortable emails.

Dun sends them for you, on schedule, with the right tone at the right time. Your clients pay. You never have the awkward conversation.