> ## Documentation Index > Fetch the complete documentation index at: https://www.twicecommerce.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # How to scan a unit onto an order > Scan a stock item's code with its order open to put that unit on the line waiting for it, and answer the order when it asks where the unit goes. > [card] [Open in TWICE Admin](https://admin.twicecommerce.com/orders) > > orders Scan the code on a unit while its order is open, and the order puts that unit on the line waiting for it, whether the line is a rental, a booking or a sale. [Auto-Fulfillment](https://www.twicecommerce.com/docs/concepts/orders/auto-fulfillment.md#scanning-a-unit-onto-an-order) explains which line a scanned unit goes to. ## Prerequisites > [!WARNING] > > **Required permissions:** **Create and edit orders** (`orders:order_summary:manage`) to put a scanned unit on the order. Without it, a scan on an order only finds orders. Every built-in role holds it, Member included. See [Users & Roles](https://www.twicecommerce.com/docs/settings/users-roles.md). > [!NOTE] > > **Have ready before you start:** > > * **A barcode scanner** connected to the computer, and units with their codes on them. See [Add a stock code](https://www.twicecommerce.com/docs/guides/inventory/add-a-stock-code.md). > * **An open order** with a line that is not handed out yet. A closed order takes order numbers only, so reopen it first. See [Reopen an order](https://www.twicecommerce.com/docs/guides/orders/reopen-an-order.md). ## The walkthrough **1. Open the order** Find the order in **Orders** and open it. If your account has more than one location, check the location selector in the top-left corner first, because the table lists only the orders of the location it shows. ![The Orders table on the All tab, with one order's row highlighted](https://mintcdn.com/twicecommerce/R8T_XUXwQgzkyGWI/images/guide-scan-a-unit-onto-an-order-01.webp?fit=max\&auto=format\&n=R8T_XUXwQgzkyGWI\&q=85\&s=eca3cc667c9432f895a0640208e4d7dc) **2. Pick the customer's card** On the **Summary** tab, click an empty part of the card of the customer you are serving. Its border changes colour, and a scan looks for a line on that card first. With one customer on the order, the card is already picked. ![An order's Summary tab with two customer cards, the Summary tab and the picked first card highlighted](https://mintcdn.com/twicecommerce/R8T_XUXwQgzkyGWI/images/guide-scan-a-unit-onto-an-order-02.webp?fit=max\&auto=format\&n=R8T_XUXwQgzkyGWI\&q=85\&s=eaa47f7600745c9717a9869b8e46672d) **3. Scan the unit's code** Scan the code on the unit. There is no field to click first, but keep the cursor out of text fields such as **Note**. When the unit fits a line waiting for one, that line flashes, its **Item Code** shows the unit's code, and **Item assigned** confirms it. ![The Summary tab right after a scan, the line's new Item Code and the Item assigned message highlighted](https://mintcdn.com/twicecommerce/R8T_XUXwQgzkyGWI/images/guide-scan-a-unit-onto-an-order-03.webp?fit=max\&auto=format\&n=R8T_XUXwQgzkyGWI\&q=85\&s=298ecdebc304ebd01dfc60bb12722e0b) **4. Choose the line, if the order asks** If the unit fits several lines equally well, a dialog headed **Which item gets** and the unit's name opens. Each option names the customer and the item, with its dates and current unit. The first one is picked already. Pick the line the unit is for and click **Assign**. ![The Which item gets dialog with two lines offered, the heading, the picked line and the Assign button highlighted](https://mintcdn.com/twicecommerce/R8T_XUXwQgzkyGWI/images/guide-scan-a-unit-onto-an-order-04.webp?fit=max\&auto=format\&n=R8T_XUXwQgzkyGWI\&q=85\&s=1de3ce079edd2bbe4b94c637c2e0e386) **5. Confirm the replacement, if the order asks** If the line already shows another unit, **"Put this unit on instead?"** opens and names the code the line was set to go out with. Click **Assign it anyway** to put the scanned unit on the line. Click **Leave it** to keep the unit it had. ![The Put this unit on instead? dialog, its heading and the Assign it anyway and Leave it buttons highlighted](https://mintcdn.com/twicecommerce/R8T_XUXwQgzkyGWI/images/guide-scan-a-unit-onto-an-order-05.webp?fit=max\&auto=format\&n=R8T_XUXwQgzkyGWI\&q=85\&s=501164f8e77d0010aecb057f4601598e) **6. Decide on a unit held elsewhere, if the order asks** If an order or a reservation holds the unit over the line's dates, a dialog opens with the unit's code and **is already reserved** in its heading. Each row says who holds the unit and what happens to them if you take it. Click **Assign it here** to take it, or **Leave it**. ![The is already reserved dialog, its heading, the row naming the other order that holds the unit, and the Assign it here and Leave it buttons highlighted](https://mintcdn.com/twicecommerce/R8T_XUXwQgzkyGWI/images/guide-scan-a-unit-onto-an-order-06.webp?fit=max\&auto=format\&n=R8T_XUXwQgzkyGWI\&q=85\&s=8cff353ffa250604e3776c077c362c92) **7. Check the line** On the **Summary** tab, check that the line shows the scanned unit's code under **Item Code**. With the default states, the line's state reads **Assigned**, the state for a unit staff put on by hand. ![The Summary tab after the scan, the line's new Item Code and its Assigned state highlighted](https://mintcdn.com/twicecommerce/R8T_XUXwQgzkyGWI/images/guide-scan-a-unit-onto-an-order-07.webp?fit=max\&auto=format\&n=R8T_XUXwQgzkyGWI\&q=85\&s=a56d560e5f488591fccf10d2906af2be) ## How do I know it worked? * **The line shows the unit's code** under **Item Code** on the order's **Summary** tab, in the state your account gives a unit staff assign, **Assigned** by default. * **A second scan of the same unit ticks its line** instead of assigning it again. Click **Unselect** at the top of the order to clear the tick. * **The unit is no longer free** over the line's dates for another order to take. ## Troubleshooting / common pitfalls > [accordion] Nothing happens when you scan, or a message appears instead > > A scan does nothing while the cursor is in a text field, so click an empty part of the page. Otherwise the message gives the reason: an open panel, a closed order, or a SKU code instead of the unit's own. See [Stock codes](https://www.twicecommerce.com/docs/concepts/inventory/stock-codes.md#qr-codes-and-barcode-scanning). > [accordion] The scan opened Add Line Item instead > > The unit fits no line waiting for a unit. It is not a **Full match** for any line, or every line already has a unit staff put on it or is handed out. Click **Cancel**, and assign the unit by hand from the line's stock item panel. See [Auto-Fulfillment](https://www.twicecommerce.com/docs/concepts/orders/auto-fulfillment.md#scanning-a-unit-onto-an-order). > [accordion] A dialog says it did not find the unit for your customer > > The only line the unit fits is on another customer's card than the one picked. Click **Assign to** and their name to put it there, or **Cancel**, then pick the right card and scan again. See [Auto-Fulfillment](https://www.twicecommerce.com/docs/concepts/orders/auto-fulfillment.md#scanning-a-unit-onto-an-order). ## Related articles > [card] [Auto-Fulfillment](https://www.twicecommerce.com/docs/concepts/orders/auto-fulfillment.md) > > How the first unit is picked, and which line a scanned unit goes to. > [card] [Stock on an order](https://www.twicecommerce.com/docs/guides/orders/assign-stock-items) > > Every task about the unit behind an order line. > [card] [Swap a stock item](https://www.twicecommerce.com/docs/guides/orders/swap-a-stock-item.md) > > Pick a different unit for a line from the list instead of scanning. > [card] [Scanning and editing stock](https://www.twicecommerce.com/docs/guides/inventory/stock-codes-and-barcodes) > > Give units codes you can scan, collect them by scanning outside an order, and act on the whole pile at once. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.