Is a carrier required to pay interest on my holdback, and is there any guarantee I’ll ever see that money again?
No and no. The issue of earning interest on a holdback is something that should be dealt with in the owner-operator/carrier contract. Some carriers do and some don’t pay interest. They all should, but it’s up to the owner-operator to ask for it.
As for the issue of getting the money back again, well... The money is held by the carrier as a means of covering any charges to the owner-operator’s account that the carrier might not be able to recover after the the two have parted company. Most agreements state the money will be paid back with 90 days or so if no other charges are incurred. We’ve all heard the horror stories about trying to get the money back, so let those stories be a lesson in the need to negotiate a contract with the carrier that better protects your interests in the deal. And, keep your eye on your account. If you don’t owe the carrier any money when you leave, you should see all that money come back to you within the specified time.