So one would think this is a no brainer as you can now read and update multi-value fields in SharePoint Online. In August of 2018, Microsoft announced that multi-value choice fields can now be read from and updated (see this link). What wasn’t clear is that it doesn’t allow you to do this with SharePoint On-Prem environments via the data gateway. I have received confirmation from Microsoft that this is, in fact, a limitation for SharePoint 2013 and 2016 on-prem environments, but shouldn’t be for SharePoint 2019. I haven’t yet tested this claim but will update if the information is untrue. So in this post, I will be inserting values in multi-value SharePoint on-prem choice fields with Microsoft Flow. I would like to send a thank you to Rob Windsor who got me started on the path to determine the solution.