Changing the Unit of Measure on an Item - It Can Be Done!

"Help! I selected the wrong unit of measure on my item!" It's more common than you know, and if you're new to AX or if you are just working quickly while setting up an item and you set up the wrong unit of measure (UOM), do not despair! You do not have to start over from scratch. There is a trick to quickly and easily get your item UOM back on track.

Changing the Unit on an Item in AX

When you first set up an item, the default UOM is usually set to ea. Let's say you wanted to set your item up as UOM lb, but hit enter before you changed the UOM. It happens, right?


The first thing you tend to do immediately is open your item and go to the first UOM you see, which is under the Purchasing tab. You try to change it, and more than likely you will receive a message that the Unit conversion from ea to lb does not exist (unless your company has a conversion set up for this). We receive this error "Unit conversion from ea to lb does not exist." because these UOMs are not from the same unit class.

This Infolog causes more hair pulling than it should!

Do not worry! You have not broken AX and there is a really easy fix for this! Any user who sets up items in AX needs to know this trick. It's a life changer.

Here is how you can change a UOM that has been entered incorrectly upon item creation:

1. Open your item for editing.
2. Navigate to the Manage inventory FastTab.
3. Find the Inventory unit and change this first.
4. Then change the Purchase and Sell units in the Purchase and Sell FastTabs if needed.

That's it! This will also update the Manage costs Unit for you as well to match the new UOM that was assigned in Manage inventory.

If Transactions Exist, Can The Unit Be Changed?

Sometimes you may not realize that an item was created incorrectly until transactions exist on the item. You will inevitably get this error message when you attempt to make the change: "The inventory unit for item ### cannot be changed because transactions exist. If the transactions cannot be deleted you will need to use a new item number with a new inventory unit."

When transactions exist, all may not be completely lost!

This infolog says it all! It can be changed back if the transactions are removed from AX. For example, if it was just added to a purchase order, you can still take it off the PO and change the UOM on the item. If it has been received and invoiced, you are looking at a much more tedious process and might be better off creating the item with a new item number.