Cross Account Alias Records

I can confirm this is still working, it's just the docs and UX of the portal are terrible.

I wanted to create a CNAME to an ALB at the apex (root) of my hosted zone; this isn't allowed so using an Alias A record instead. My ALB is in a different account, so the UI makes you think you can't do it... but you can.

You can create an Alias record to an ALB/ELB in another account by just pasting into the 'Route traffic to' box. Choose the region, then just dump the address into the box. Now this UI element makes you think it's a normal picklist and you can only pick from valid values... but it is secretly also a textbox allowing you to enter arbitrary text. Great UX guys 👏🏼

So enter your address and just click 'Create records'.

So I've found the solution. You can in fact create an Alias record to a resource in another account.

The answer is in the documentation although it's description is a little vague in my opinion. See here under the ELB heading.

If you used different accounts to create your Amazon Route 53 hosted zone and your load balancer – Enter the value that you got in the procedure Getting the DNS Name for an ELB Load Balancer.

As a result, here's what I did:

1. Copied my ELB DNS name from account B
2. In account A, I created an Alias record for my zone apex (type: IPv4) and I simply pasted in the DNS name into the text field.

I saved the record and it worked straight away.

After you paste in your ELB's DNS name, you'll notice that the Alias Hosted Zone ID matches the Hosted Zone ID in your ELB's description tab.