To run VAST XML creatives on Guaranteed, Promotional or Backfill Line Items targeted to Phone or Tablet Fullscreen ad units, follow these steps:

1. Create a new Guaranteed, Promotional or Backfill Line Item.



2. Target the line item to Phone or Tablet Interstitial ad units.



3. You will be taken to the Line Item Details page. Click on ‘Add a New Creative.’



4. From the Format drop-down, select Phone Full Screen or Tablet Full Screen. You will see the VAST Video Radio button. If you select any other option, you will not see the VAST Video radio button option.



5. Check the Landscape box (if applicable); and fill in the creative name and Conversion Tracking ID.
6. You will see a field called “VAST XML.” Paste in valid VAST XML. If you paste in invalid VAST XML, you will see an error message. Once you’re done, click ‘Save’ at the bottom right.

   For guidelines on the types of VAST assets and formats of tags that the UI will validate, check out this article.

Go back to Self-Testing Your Creatives article.