How to Use an XML Parts List on BrickLink & Brick Owl

Downloaded an XML parts list for a custom MOC model but not sure what to do next? You do not need to search for every piece manually. A compatible XML list can help you organize the part numbers, colors, and quantities required for a build, then use a parts marketplace to find sellers.

In this beginner-friendly guide, we'll walk through how to use a BrickLink-format XML parts list, how to import it on BrickLink and Brick Owl. We'll also cover common upload errors and how to compare the real cost of ordering your parts.

Quick links: Where do I use my XML parts list?

Marketplace	Where to start	What to expect
BrickLink	Wanted List XML upload page	Paste the XML text into the Upload BrickLink XML format tab.
Brick Owl	Wishlist import page	Import a compatible BrickLink-format XML parts list into a wishlist.

Important: You may need a free account on the relevant marketplace to save a wishlist. Importing a list does not purchase any bricks.

What is an XML parts list?

An XML file is a structured text document. For brick building projects, it can identify each part and the color and quantity you need. A BrickLink Wanted List XML is especially useful because marketplaces and building tools can recognize its part identifiers.

For example, a simplified BrickLink-compatible entry looks like this:

<INVENTORY>
  <ITEM>
    <ITEMTYPE>P</ITEMTYPE>
    <ITEMID>3001</ITEMID>
    <COLOR>11</COLOR>
    <MINQTY>4</MINQTY>
  </ITEM>
</INVENTORY>

Here, ITEMID identifies a part, COLOR identifies its catalog color, and MINQTY means how many you want. Real files normally include many ITEM entries. An XML parts list is not a building instruction PDF.

Before you begin: Download and open the XML file

1. Download the .xml file supplied with your model's building instructions or parts list.
2. Save it somewhere easy to find, such as your Downloads folder.
3. On Windows, right-click the file and select Open with → Notepad. On Mac, use a plain-text editor such as TextEdit in plain-text mode.
4. You should see text beginning with <INVENTORY> and ending with </INVENTORY>, with individual parts between them.

Tip: If clicking a download link opens the XML in your browser rather than downloading it, try right-click → Save link as, or save the displayed XML as a file ending in .xml. Do not copy the browser's message that says the XML has no style information.

How to upload an XML parts list to BrickLink

Open BrickLink's Wanted List upload page →

1. Sign in at BrickLink.com.
2. Open the Wanted List upload page.
3. Select the tab labeled Upload BrickLink XML format. This is different from Upload a file from your computer, which is intended for other supported design-file formats.
4. Open your XML file in Notepad or another plain-text editor. Press Ctrl+A (or Cmd+A on Mac) to select all the text, then Ctrl+C / Cmd+C to copy it.
5. Return to BrickLink and paste the XML text into the large input box.
6. Under Add to, choose Create New Wanted List or select an existing list. Naming your list after the model makes it easier to manage.
7. Click Proceed to verify items. Check that the recognized parts, colors, and quantities are correct.
8. Confirm with Add to Wanted List once everything looks right.

Why can't I just select my XML file? BrickLink's XML workflow uses a paste-text tab. Its separate file uploader is for formats such as Studio .io and BrickStore .bsx; choosing an XML file there may produce an unsupported-format message.

How to find and buy the parts on BrickLink

After creating the list, open your Wanted Lists to review the parts. Then go to Buy Wanted Lists, select the relevant list, and look for stores that carry the parts you still need. Review condition, quantity, shipping destination, minimum order requirements, and the full total before checking out.

For a visual reference, BrickLink's official Wanted List upload instructions explain the XML format and upload options.

How to import an XML parts list into Brick Owl

Open the Brick Owl wishlist import page →

1. Log in to BrickOwl.com.
2. Open the Wishlist Import page.
3. Choose the available BrickLink XML import option and follow the form's prompts. If the page asks for XML text, open the file in a text editor, copy the complete contents, and paste them into the import box.
4. Create a new wishlist for your model, or choose an existing wishlist if the import page offers that option.
5. Review the matched parts, colors, and quantities before saving.
6. Open your wishlist and check the available sellers and purchase options for the parts you need.

Brick Owl's catalog may not use precisely the same item identifiers for every part. If anything cannot be matched automatically, verify the part and color manually rather than replacing it with a visually similar but incompatible piece.

BrickLink vs. Brick Owl: Which should you choose?

Your goal	Suggested starting point
Import a BrickLink-format XML parts list quickly	BrickLink — direct XML text-to-Wanted-List workflow
Use an alternative wishlist-based parts marketplace	Brick Owl — XML wishlist import page

There is no universal cheapest marketplace. The final price depends on part availability, condition, seller location, shipping, and the number of separate orders. Whenever possible, compare total checkout costs, not only individual part prices.

Common XML parts list problems and fixes

“Unsupported file type” on BrickLink

You are probably on the Upload a file from your computer tab. Switch to Upload BrickLink XML format and paste the XML as text.

“Invalid XML” or “Content is not allowed in prolog”

Check for text before the first <INVENTORY> tag. BrickLink's upload instructions say not to include the XML declaration, such as <?xml version="1.0"?>. Remove that declaration if present, but do not remove part entries or edit their identifiers at random.

A part is missing or the color looks wrong

Different marketplaces sometimes use different catalog mappings. Verify the part ID, mold variation, and color. If a substitute is offered, check that it fits the model rather than assuming identical appearance means identical function.

The XML opened as a web page instead of downloading

That is normal for some browsers and file-hosting setups. Save the file to your device or copy its source text into a plain-text editor, keeping the XML structure intact.

Do I need to order every part in the XML?

No. Check your existing collection first and remove or mark the quantities you already own. For some models, you may also already have suitable spare parts at home.

Ready for your next build?

Explore the HTBI Build Hub for more creative MOC projects and building ideas. When a model includes a downloadable XML parts list, use the steps above to turn that list into an organized plan for finding the pieces you need.

Marketplace menus and import features can change. This independent educational guide is not affiliated with BrickLink or Brick Owl.