Not able to find my running EC2 instance and ELB

Hello.

If you check the domain using the "nslookup" command, you can see the EC2 domain, so I think it's an AWS domain.

nslookup
> 16.170.240.166
166.240.170.16.in-addr.arpa     name = ec2-16-170-240-166.eu-north-1.compute.amazonaws.com.

First, check the global view from the URL below and check which region EC2 is located in and whether it exists in your account.
If you have multiple AWS accounts, I recommend investigating all of them.
https://us-east-1.console.aws.amazon.com/ec2globalview/home?region=us-east-1#

Trying to untangle this - you have two accounts, and in one of them there is an EC2 instance with public IP 16.170.240.166 - this resolves to ec2-16-170-240-166.eu-north-1.compute.amazonaws.com

Account #1 you can login to this, and it doesn't have any EC2 instances running in eu-north-1. The payment method is an expired credit card. And there are no old invoices or previous bills for you to review. But the main thing is you can login to it.

Account #2 if this is your only other account then it must be this one with the EC2 running in Stockholm. But you don't know which email address is associated with it.

You already know that you need to identify the root account email address for Account #2. Advice on doing this is here https://docs.aws.amazon.com/IAM/latest/UserGuide/troubleshooting_root-user.html

If you still can't identify it then go to https://support.aws.amazon.com/#/contacts/aws-account-support/ and choose

• Inquiry type: Unable to Sign In

Then put as much information as possible in the How can we help you section. This will engage direcdtly with AWS - the re:Post community has no way of accessing billing or account details of anybody.

Some of the other points:

I also set a cost alerts to alert me if I am running out my free tier plan and they are sent to my company email.

Are these alerts being sent to the email address associated with Account #1 - which you can access, and are reasonably happy with? Or is it sent to an email that is not associated with Account #1, and so could be an email address associated with Account #2 ?

Also set up a company details for invoices etc.

Same question about this, which email address are the invoices being sent to? Is there a 12-digit AWS account number on any invoices you are receiving (don't post it here)?

the credit card that is entered is expired. Could someone help with that?

You should be able to update the payemnt method here https://console.aws.amazon.com/billing/home#/paymentpreferences