The quick answer
On the assembly item, Enable Lot Auto Numbering and a Lot Number Format on the Lot Numbering subtab tell NetSuite how to name each lot. On Build Assemblies, click the Inventory Detail icon beside Quantity to Build, type a Quantity (and an Expiration Date if the lot expires) and click Add. The Lot Number fills in from the format. The number is used, and the item's Current Sequence Number moves up, when you save the build.
The screenshots show sample data. Person and operating-company names are fictional. Use your own records and values when following the steps.
Before you start
You need the Lot Auto Numbering SuiteApp, Lot-Numbered Inventory and Assembly Items turned on. The assembly needs a bill of materials, its components need to be in stock, and your role has to be able to build assemblies and open the Lot Auto Numbering records. Without the SuiteApp or the access, NetSuite opens the standard Inventory Detail popup and you type every lot number yourself. The posting period has to be open, and if your account builds assemblies through work orders, use that process instead of Build Assemblies. The subtab and field labels come from the SuiteApp and can differ a little between versions, so match the labels on your own item. In this example, Example Supply Co. makes FH-220 Herbal Rinse, a lot-numbered assembly stocked in liters at Portland Plant, from FH-120 Herbal Concentrate.
01. Check how the assembly numbers its lots
Open the FH-220 Herbal Rinse item and click the Lot Numbering subtab. Enable Lot Auto Numbering is checked, the Lot Number Format is RN-HB, the Initial Sequence Number is 40 and the Current Sequence Number is 52. The current number is the one the next lot will use.
Click RN-HB. A Lot/Serial Number Format is an ordered list of elements. This one has the text RN-, the Day of the transaction date in two digits, the text -HB-, and the Sequence Number. For a build dated the 19th with the sequence at 52, the next lot is RN-19-HB-52.
A format can use other elements, such as other parts of the date, so read the format record instead of assuming the pattern.
02. Start the build
Go to Transactions > Manufacturing > Build Assemblies. Choose Fernhill US as the Subsidiary, Portland Plant as the Location and FH-220 Herbal Rinse as the Assembly. The Bill of Materials fills in as FH-220 Herbal Rinse BOM, the revision as Rev 1, and the Date reads 11/19/2026.
03. Enter the quantity
Type 6 in Quantity to Build. NetSuite works out each component quantity from the bill of materials, so the Components subtab shows FH-120 Herbal Concentrate at 6 liters, one liter for every liter built. Check those quantities and the Buildable Quantity before you open any inventory detail.
04. Let NetSuite generate the lot number
Click the Inventory Detail icon in the header, beside Quantity to Build. Because the assembly is lot numbered and uses the SuiteApp, the popup is Lot Auto Inventory Detail, not the standard Serial/Lot Number list. Type 6 as the Quantity and 11/19/2027 as the Expiration Date, leave Status at Good, and click Add. The quantities on the lot lines have to add up to the Quantity to Build. The Lot Number column fills in right away: RN-19-HB-52. That is RN-, the 19th, -HB- and the sequence 52. Click OK to return to the build.
Nothing is committed yet. In this account, closing the popup or leaving the build without saving left the number unused, and the next build was offered the same one.
05. Assign the component lot
Back on the Components subtab, click the Inventory Detail icon on the FH-120 Herbal Concentrate line. Choose the lot HC-261102-07. Its bin PP-A1, status Good and expiration date fill in. Type 6 as the Quantity, click Add, then OK. If one lot cannot cover the whole quantity, add a line for each lot so the quantities add up to what the component line needs. The component lots do not take part in naming the finished lot. They only record which lots the build consumed.
06. Save and check what changed
Click Save. Assembly build ASSYB6320 is created.
Click the build's Inventory Detail icon. The saved lot RN-19-HB-52 is listed with status Good, expiration date 11/19/2027 and quantity 6.
Open the FH-220 Herbal Rinse item again and click Lot Numbering. The Current Sequence Number is now 53, so the next lot ends in 53.
Check the result
- The saved build's Inventory Detail lists RN-19-HB-52 with status Good, expiration date 11/19/2027 and quantity 6.
- The lot number matches the format: RN-, the day of the build date, -HB- and the sequence that was current.
- The item's Current Sequence Number is one higher than before the build.
Common questions
What do Lot Number Format, Initial Sequence Number and Current Sequence Number mean?
Lot Number Format is the Lot/Serial Number Format record the item uses to build its lot numbers. Initial Sequence Number is where the counter started. Current Sequence Number is the value the next lot will use, and it goes up each time a lot is committed.
When does the lot number appear, and when does the sequence go up?
In the account used for this walkthrough, the lot number appeared in the Lot Number column as soon as Add was clicked in the Lot Auto Inventory Detail popup, and the Current Sequence Number went up when the build was saved. A build that was discarded without saving left the counter alone, and the next build was offered the same number. Check this against your own SuiteApp version before you rely on a number from an unsaved build, especially when several people build the same item.
Does the finished lot take its expiration date from the component lots?
Not in the account used here. The component lot had its own expiration date, and the finished lot had none until a date was typed on the Lot Auto Inventory Detail line. Unless a customization derives one date from the other, enter the finished lot's expiration date yourself according to your shelf-life policy.
Why do I see the standard Inventory Detail popup and not Lot Auto Inventory Detail?
Lot Auto Inventory Detail comes from the Lot Auto Numbering SuiteApp. If the item does not have Enable Lot Auto Numbering checked and a Lot Number Format chosen, or the SuiteApp is not installed or your role cannot use it, NetSuite shows the standard popup and every lot number is typed by hand. Check the item's Lot Numbering subtab first, then your role's permissions.
Can a lot number format use more than text, a day and a sequence?
Yes. A format is an ordered list of elements, and elements can include other parts of the date. Open the Lot/Serial Number Format record to see the elements an item actually uses.
Do the component lots affect the finished lot's name?
No. Each lot-numbered component has its own Inventory Detail icon on the Components subtab, and the lots consumed, their bins and quantities are chosen there. The finished lot's name comes only from the item's format and sequence.
Where do I see the cost or the GL impact of the build?
Not in Inventory Detail. That popup lists the finished lot, its status, expiration date and quantity. The build shows a Projected Value, and after you save you can review the accounting on the GL Impact subtab. The result depends on the item's costing method and your accounting setup.
Which date does the Day element use?
In the account used here, the Day in the lot number matched the date of the build. An earlier build dated the 17th had a 17 in its lot number. Other transaction types may take the date from somewhere else, so check the format on the transaction you are using.
Can I use more than one component lot on a build?
Yes. Add one line for each lot on the component's Inventory Detail popup, and make the quantities add up to the quantity the component line needs.