The short answer
Keep a list of every can that's past its included days, and call those customers on a routine: every day or every week, the same way. Write down each call and when to call again. Cans go missing when nobody owns the list, so make it somebody's job.
By American Dumpster Software, the software built by American Roll-Offs, a roll-off company in Jacksonville, Florida. Updated .
Why cans sit
Cans that sit too long are rarely stolen. The job finished and nobody called for the pickup. The contractor moved on to the next site. The homeowner forgot. Or the can was swapped and the old one never got recorded as home. Each of those is fixed by the same thing: knowing which cans are out, since when, and who to call.
Work out what it costs you
A can that's out and not earning is a can you might have to buy to cover another order. To see what sitting cans cost you, count the cans out past their included days on a normal day, and multiply by what a rental of that size earns you per day. That number is usually enough to make the call list somebody's job.
Make a call list, and work it
Every day, list the cans past their included days, oldest first. For each one, call the customer and ask: pickup, swap, or keep it longer at the day price? Write down the answer and a date to call again.
Start with the oldest cans and the customers who owe you money: a can out for weeks on an unpaid account is the one most worth a call today.
Booked pickups should come off the list by themselves, so the office only calls the ones that need it.
Catch the missing ones early
A can that isn't where the list says it is should be found fast. Count the yard against the screen now and then. When a driver finds a can at the wrong site, or a different number than expected, it should be flagged for the office, not fixed quietly on the truck.
Set the rule in the agreement
Say in the rental agreement how many days are included, what each day after costs, and that the can stays your property. That makes the call easy: you aren't asking a favor, you're reminding them of what they signed.
How the software does it
In American Dumpster Software, the Dumpsters call list shows every can past its included days (or past your own red-after days when there's no day limit); a booked pickup or swap takes a can off. Log a call keeps a note and a date to call again. Every can has its own story, the yard count checks the yard, and cans found in the wrong place are flagged for checking. See it in the live demo, and what's included on Pricing.