How long can I legally wait to send an invoice to collections?

Short answer: there is no legal deadline. You can hand an invoice to a collections agency the day it goes past due, or you can wait three years. The federal statute of limitations on most written contracts ranges from three to ten years depending on the state, so the legal window is wide.

The practical window is much narrower. Recovery rates drop from roughly 87 percent on invoices worked inside the first week past due to roughly 11 percent on invoices that hit day 90 with no human contact. The math is brutal: every week you wait, a chunk of recoverable balance turns into bad debt.

Most small business owners wait far too long. A 2023 receivables analysis across 4,200 small service businesses found the average lag between an invoice going past due and the first serious collection attempt was 47 days. By that point, the customer has mentally written off the debt — the money was earmarked for something, then spent. It exists on your books and nowhere else.

The right framework is not 'when do I send to collections' but 'when do I make first call'. Day three past due is the standard inflection point. The customer still has the invoice in their head. The conversation is gentle. About 85 to 90 percent of overdue invoices in the first three weeks are simply forgotten or waiting on a cash-flow event — those calls close on the first attempt.

Sending to a third-party collections agency is a different decision. Agencies typically charge 30 to 50 percent of recovered amount, only engage at day 90 or later, and almost always end the customer relationship because federal law (FDCPA) requires their callers to identify as debt collectors. If the customer is someone you might want to do business with again, agency referral is a one-way door.

First-party AI-voice follow-up sits in the middle. The agent calls on day three, identifies as calling on behalf of your business (not as a collector), takes payment, and routes any dispute back to your office. Pricing is typically a success fee — Syntharra charges ten percent of recovered amount, no monthly fee. See /ai-invoice-collection for how that works end to end.

State-level rules add a layer on top of the federal floor. California, Florida, Illinois, Massachusetts, New York, and Texas all have specific calling-window restrictions and recording-consent rules that apply to outbound voice. The state-by-state breakdown lives at /collections-laws. The TCPA federal floor — 9 AM to 8 PM in the customer's local timezone, no weekends — is the same everywhere; state law extends it.

Practical playbook: call on day three (preferably automated and compliance-enforced). Call again on day six and day nine if no contact. Pause if the customer disputes the work. Send to a collections agency only after day 90 if the customer has gone fully silent and the relationship is already dead. Most invoices never reach the agency stage if the day-three call happens.

If you want to model how this changes your own DSO, the DSO calculator takes your aging report and shows you the cash-flow impact of moving the first-call date from day 47 to day three.