Measure the internal gap first.
Take completed jobs from last month and measure two intervals: work complete to invoice issued, and invoice issued to payment received.
Owners generally assume the problem is the second interval. It is frequently the first, and the first is entirely within your control — no customer behavior has to change to fix it.
Invoice from the work, not from the office.
When completion lives in a field system and invoicing happens later from an accounting system, someone has to move it across. That person is busy, so it happens in batches, and the batch is the delay.
Connecting those two systems removes days from every job at once, and it also removes the jobs that quietly never get invoiced at all — which is a bigger number than most businesses expect and is invisible by construction.
Ask at the moment of highest goodwill.
The best moment to be paid is while the customer is standing in front of the finished work and pleased with it. Every day after that, enthusiasm declines and other bills arrive.
Where the job allows it, take payment on site. Where it does not, make sure the invoice arrives the same day rather than at the end of the week.
Make the route obvious, and the chasing automatic.
Every additional step between wanting to pay and having paid costs you days. A payment link that works on a phone, without an account to create, removes most of that.
Then automate the reminders. Chasing is nobody’s favorite task, so it gets done when things are quiet — which is exactly when there is least to chase. An automatic, polite sequence that stops the moment payment arrives outperforms a person on their best week.
And handle failed recurring payments deliberately. Where there are maintenance plans or subscriptions, silent card failures are a steady leak that nobody notices because nothing happens.