This feature allows you to automatically pass values entered in the parent form right into the related child forms, without having to re-enter anything manually.

Associated Items field will read the values of the parent item columns and pass them to the child New form automatically, in the query string. Field values are being read directly from the form, hence the parameters generation will work only from parent item's New / Edit form.

Almost all column types are supported and there is nothing to configure, it happens automatically. Now all we need to do is to use these value to set the default value for the columns on the child form. Default value setting are here to help.

NOTE: setting columns default values are a feature of Ultimate Forms: Forms, so without it being installed, this process will not work.

Supported column types:

• Text
• Number
• Currency
• Date Time
• User
• Yes / no column
• Choice
• Multi choice
• Color Choice
• Lookup
• Multiple lookup
• Connected field
• Multiple Connected field

Note: Parent form fields must be on the parent form and are set as read or write permissions to be able to pass the value as a iwfv_ field. The field name to use with the iwfv_ prefix would be the internal name of the field (you can find that in the list settings > field config URL)  

Also, note that the prefix iwfv_ is to be used in M365 Sharepoint Online, whereas the older prefix iwfv (with no underscore) would be for the On-prem environments. In Modern forms, you will use iwfv_ in both SharePoint Online and on premises.

Full functionality example is available in the blog post: Passing values to related forms from a parent form