Elastic IP Address Limits

There is some useful information here you may want to check out: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-byoip.html ahd here: https://aws.amazon.com/blogs/networking-and-content-delivery/introducing-bring-your-own-ip-byoip-for-amazon-vpc/

Regarding your specific question...

1. Elastic IP Limit with BYOIP:

The default limit of 5 Elastic IPs per region applies to IPs that Amazon provides you, not the ones you bring yourself. When you bring a /24 IPv4 address range (which contains 256 addresses), you can allocate all of these as Elastic IPs in your VPC without affecting or being affected by the standard Elastic IP quota.

This is different from another service quota limit, per the documentation I linked above:

"You can bring a total of five BYOIP IPv4 and IPv6 address ranges per Region to your AWS account. You cannot adjust the quotas for BYOIP CIDRs using the Service Quotas console, but you can request a quota increase by contacting the AWS Support Center as described in AWS service quotas in the AWS General Reference."

*Related Note: On Friday, July 28, 2023, AWS announced they would begin charging for every IPv4 address an account is allocated or using on the platform, starting February 1, 2024. That’s a change from the current scheme, which only charges you for addresses you reserve, but aren’t using, or if you reassign the same address over a hundred times a month. These charges don't apply to you, but it demonstrates your BYOIP strategy will have an even higher ROI for you next year than it does this year due to the change in pricing by AWS. Nice work!

See: https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address-charge-public-ip-insights/