building up assembly items

Thanks for the details, New Beginning 2021.

I'm here to share some information on how to handle labor cost.

Currently, QuickBooks Desktop isn't able to handle landed costs, however, I have a workaround that you may want to consider.

On each item, you can add portion of the shipping. Then, when creating a bill, manually enter the quantity received on each items and then enter the item cost plus a portion of the shipping. When you click out of the total cost, the system will do the per item rate.

You can use a clearing expense or asset account when paying the bill. Then, modify the original bill for each item and increase the item's total cost by a portion of the third-party shipping. Afterwards, select the clearing account or asset account and then enter the full amount as a negative number.

Upon clicking Save & Close, you'll be prompted with any warnings about payments applied. The system, will redo the purchase cost of each item as of the date of the bill. Whenever an item, have been sold, QuickBooks will make COGS adjustment resulting from the increased per item cost.

Here's an article to know more about adjusting inventory value (Scroll down until you reached the Adjust the value of an inventory item section): Adjust inventory quantity or value.

If you need assistance in doing this, you can reach out to our Phone Support team.

Let me know if you have other concerns. I'll be happy to help you out. Keep safe!

so please advise what is the best way to build the assembly then? 

what to add beside the raw materials costs to build the assembly 

Thanks for getting back to us, @new beginning 2021,

As mentioned by my peer above, you can add a portion of the shipping cost by manually entering the quantity received on each items as a workaround. This way, it'll override the item's amount on your bill. See the above recommendations for details.

On the other hand, you can create a service item for your costs and fees. This way, you can include them in your assembly build. Here's how:

1. Go to Lists.
2. Select Item List.
3. Edit your existing Inventory Assembly item.
4. Scroll down towards the Bill of Materials section. Then, tick on the next line item.
5. Tap Add New. Choose Service on the Type drop-down and then type "Assembly Cost" for the Item Name.
6. Enter all other cost or item info. Then, make sure to mark the box next to This service is used in assemblies or performed by a subcontractor or partner box.
7. Click OK.

Below is the image of how it looks like.

Learn more about assemblies in these guides: 

• Track the products you manufacture.

• Combine your inventory items to build finished goods.

• Understand inventory assets and cost of goods sold tracking.

Additionally, here's a link that'll help you in creating and running inventory reports: Inventory reports in QuickBooks Desktop.

Please know that you're always welcome to reply anytime if you have follow-up questions. Have a great day ahead.