Dunning letters from your live QuickBooks or Stripe data
Every open invoice, days-overdue computed, merged into a firm-but-friendly letter, batch-generated in one click.
Unsent letters are uncollected revenue
Overdue invoices don't chase themselves. Everyone knows a written past-due notice gets invoices paid, and almost nobody sends them, because the manual version is miserable: export the invoice list, work out who's actually overdue and by how many days, clean up the columns, and fight Word's merge wizard. Every single month.
So the letters go out late, or only to the worst offenders, or not at all. Meanwhile the balance ages and the awkward phone call gets more awkward.
Every open invoice, one batch
MergeNinja syncs your invoices straight from QuickBooks Online or Stripe (read-only) and computes days overdue for each one. The default filter is exactly what a dunning run needs: open and past-due invoices only.
Your letter stays a normal Word document with merge fields. Hit merge, and every customer with an open balance gets their own letter: right name, right amount, right number of days overdue. Next month, the same run is one click.
How it works
- 1
Connect QuickBooks or Stripe
Read-only access: MergeNinja can see invoices, never change them.
- 2
Sync invoices, filtered to open + past due
Days overdue is computed per invoice at sync, so the data is ready for the letter.
- 3
Merge into your past-due letter
Fields like customer name, amount due, and days overdue fill in for every customer at once. Finished letters arrive in your inbox, ready to print or send.
Frequently asked questions
Can it calculate how many days an invoice is overdue?
Yes. Days overdue is computed for every invoice when the data syncs, so your letter can say "34 days past due" without you touching a formula.
Can I send different letters at 30, 60, and 90 days?
Yes. Keep one template per escalation level and filter the batch by days overdue before merging. A friendly reminder at 15 days, a firmer letter at 45, a final notice at 90.
Will the letters match my letterhead?
They are your letterhead. You upload your own Word document: fonts, logo, and layout stay exactly as you built them. MergeNinja only fills the merge fields.
Does MergeNinja send the letters to my customers directly?
The finished documents are delivered to your email as ready-to-use files. You review them, then print, mail, or attach them. You stay in control of what reaches customers.
Related
Stop exporting. Start merging.
Connect your data, upload your Word template, and send every customer document in one click.
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