If my truck's top limit for legal payload is 13,000 pounds, that would be the most i'd accept. No point in running illegal since you're the one that gets stuck with the fine if imposed. The violation goes on YOUR record, not the shippers. Also, the payload limits exist for a reason. It's unsafe to yourself and othersto run an overloaded truck.
If your carrier limit for a D load is 13,000 pound (as it is for FedEx CC), but your straight truck can legally carry more, then it's up to you if you want to carry the extra weight up to the legal limit. You might be able to negotiate a higher pay rate for exceeding the D-load weight while still hauling legal weight higher than 13,000 lbs. Or, you might decide it's no big deal to haul some extra pounds over the D-unit limit for D-unit pay and that the run is worth it as is.
The D-unit truck we're currently driving can legally carry 13,000 lbs (and just a few pounds more). It is lift-axle equipped. Twice in the last few days, we've been dispatched on loads that were quoted at around 12,800 lbs. Such offers send up immediate red flags to us, indicating that we need to be cautious the actual weight that goes on the truck. Shippers often estimate weights when seeking a truck. When the weight is that close to our legal limit, we know to be careful.
At each dock, I pressed the shipper about his or her confidence in the weight figure on the paperwork. It turned out that our caution was justified.
In one case, the fork lift driver, frustrated because he wanted to leave for the day, went inside and asked someone in the office to provide exact weights for each item being loaded, plus the weight of the skids and crating material. It turned out that for the load to come in under 13,000 lbs, two 55 gallon drums had to be left behind.
In the other case, the paperwork said the weight was 13,600 lbs. I told the shipper we could not carry that much and called dispatch. The party paying for the load was different than the shipper. Dispatch said the party did not want to split the shipment between two runs with our truck (something we would have gladly done on this very lucrative load) or split the shipment between two trucks. The party insisted the entire load must be shipped and it had to be shipped now.
Dispatch told us to stand by. We waited for an hour and low and behold, the party decided we could make the run and do it with legal weight! (There are times when dispatch really comes through). A second FedEx CC truck was then dispatched to take the remaining skids. We were fully paid for the load, as was the second truck.
We later learned from the consignee that the party in question has a hard time getting the weights right on the loads. In time they'll learn, that if they want the special services we provide, they'll have to get the weights correct and pay the freight, so to speak.
Had the party stuck to his guns and insisted the shipment all go in one truck and go that day, FedEx would have lost the load, since no E-unit was available in the area on short notice. While not preferable, it's a situation we would have accepted. It is simply not an option for us to drive an illegally-overweight truck. Forfieting the load, even one just 600 lbs over limit, would be the lesser of two evils.