How To Convert Indesign File To Older Version Link Page
How to downsave an InDesign file to open it in an older version
Alternatively, you can use the "Export" feature to convert your InDesign file to an older version. Here's how: how to convert indesign file to older version link
Here is the guide on how to do this, along with the limitations you need to know. How to downsave an InDesign file to open
If you want to look like a true industry pro to your print vendor, avoid IDML if possible. Keep your workflow in the "universal standard" for as long as you can. But if you must travel back in time, IDML is the only bridge strong enough to carry your design across the years. Keep your workflow in the "universal standard" for
Fastest and cleanest: request the original author to export a copy compatible with your version.
Adobe provides a free online tool, the InDesign File Converter, which allows you to convert InDesign files to older versions.