Sharing between two Apple ID’s

Hello ncmtgman,

It might help to know what your purpose is with this "linking". I have never heard of that but maybe there is a feature that does what you want under another name. It would also help to know if your son is a minor child, or an adult.

You can get started with Family Sharing which will let you share items:

Set up Family Sharing - https://support.apple.com/HT201088

If this is a minor child and you want some control, you can do this through parental controls and Screen Time:

Use Screen Time on your [or a child's] iPhone, iPad, or iPod touch - https://support.apple.com/HT208982 - "With Screen Time, you can access real-time reports about how much time you spend on your iPhone and iPad, and set limits for what you want to manage."