I see this question a lot, or a variation of it.
“We use inventory items to perform services on our trucks, how do we track what was used per truck and control inventory?”

There is a solution on the forums that tells you to sell the inventory items to a fake customer at cost. This solution has a couple of problems.

1. The only way to sell at cost is to first look up each item and write down the average cost for the item that is on the item screen at the very bottom. As you can imagine that is a PITA but you have to do this because that is the cost that QB will send to COGS when the item is on the sales document. …. and that is the other problem.

2. When you sell an item several things happen:

2a. You get income, in this case the income is the total cost of the items.
2b. The total cost of the items goes to COGS – an expense account.
So the income and the expense wash out- so effectively nothing has happened to the financial accounts.

But that is WRONG. When you used the inventory items to service your truck, you had an expense, the cost of the items used.

The only way I see to do it is:

Set up a class for each truck, use the truck ID number that you use for dispatching

When you use parts and supplies, bring up inventory adjust, set the adjusting account to an “in-house repairs” expense account, set the class to the truck the parts were used on, lower the qty of parts used. That sends the COST of the items used to the expense account as they should be.

Unfortunately that has to be done for each truck since you can only select one class per adjustment. But then again you should only have one work order per truck for services too.

Use the main menu Lists>Class List and then select the class list for the truck you want, and run a quick report to see totals by truck. If you set up a class list called Trucks, and then make all individual truck classes sub item, you can run one report on the parent class and get all sub-classes listed with sub totals by class.

Another nice aspect of this is that you can track any expense per truck simply by selecting the class when you have an expense, say fuel, body work, etc etc.
Debbi over at the QuickBooks forum posted another way to do it that works.Set up a service item called in-house-use or something and point it to the expense account you want to use to track this expense. In Debbies example she was talking about tracking promotional items used as advertising so this item went to the advertising expense account.

Using a sales receipt for a dummy customer

Enter the item and item cost (this requires you first look at the item screen and write down the item cost)

Enter the service item in-house-use and enter the same cost as a negative.

That works, sales and COGS record the same amount offsetting each other, and the advertising expense account records the cost while inventory is reduced.

The problem I have with this procedure is that you first have to look up the costs of each item being used, and then do the sales document. And it requires that you have an in-house item for each kind of adjustment you want to do since each item can only point to one expense account.

The same thing is accomplished by using inventory adjust and selecting the expense account – lot easier in my opinion.