Use DisassociateAddress with an Amazon SDK or CLI

    /// <summary>
    /// Disassociate an Elastic IP address from an EC2 instance.
    /// </summary>
    /// <param name="associationId">The association Id.</param>
    /// <returns>A Boolean value indicating the success of the action.</returns>
    public async Task<bool> DisassociateIp(string associationId)
    {
        var response = await _amazonEC2.DisassociateAddressAsync(
            new DisassociateAddressRequest { AssociationId = associationId });
        return response.HttpStatusCode == HttpStatusCode.OK;
    }

###############################################################################
# function ec2_disassociate_address
#
# This function disassociates an Elastic IP address from an Amazon Elastic Compute Cloud (Amazon EC2) instance.
#
# Parameters:
#       -a association_id - The association ID that represents the association of the Elastic IP address with an instance.
#
# And:
#       0 - If successful.
#       1 - If it fails.
#
###############################################################################
function ec2_disassociate_address() {
  local association_id response

  # Function to display usage information
  function usage() {
    echo "function ec2_disassociate_address"
    echo "Disassociates an Elastic IP address from an Amazon Elastic Compute Cloud (Amazon EC2) instance."
    echo "  -a association_id - The association ID that represents the association of the Elastic IP address with an instance."
    echo ""
  }

  # Parse the command-line arguments
  while getopts "a:h" option; do
    case "${option}" in
      a) association_id="${OPTARG}" ;;
      h)
        usage
        return 0
        ;;
      \?)
        echo "Invalid parameter"
        usage
        return 1
        ;;
    esac
  done
  export OPTIND=1

  # Validate the input parameters
  if [[ -z "$association_id" ]]; then
    errecho "ERROR: You must provide an association ID with the -a parameter."
    return 1
  fi

  response=$(aws ec2 disassociate-address \
    --association-id "$association_id") || {
    aws_cli_error_log ${?}
    errecho "ERROR: AWS reports disassociate-address operation failed."
    errecho "$response"
    return 1
  }

  return 0
}

The utility functions used in this example.

###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
  printf "%s\n" "$*" 1>&2
}

##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# The function expects the following argument:
#         $1 - The error code returned by the AWS CLI.
#
#  Returns:
#          0: - Success.
#
##############################################################################
function aws_cli_error_log() {
  local err_code=$1
  errecho "Error code : $err_code"
  if [ "$err_code" == 1 ]; then
    errecho "  One or more S3 transfers failed."
  elif [ "$err_code" == 2 ]; then
    errecho "  Command line failed to parse."
  elif [ "$err_code" == 130 ]; then
    errecho "  Process received SIGINT."
  elif [ "$err_code" == 252 ]; then
    errecho "  Command syntax invalid."
  elif [ "$err_code" == 253 ]; then
    errecho "  The system environment or configuration was invalid."
  elif [ "$err_code" == 254 ]; then
    errecho "  The service returned an error."
  elif [ "$err_code" == 255 ]; then
    errecho "  255 is a catch-all error."
  fi

  return 0
}

To disassociate an Elastic IP addresses in EC2-Classic

This example disassociates an Elastic IP address from an instance in EC2-Classic. If the command succeeds, no output is returned.

Command:

aws ec2 disassociate-address --public-ip 198.51.100.0

To disassociate an Elastic IP address in EC2-VPC

This example disassociates an Elastic IP address from an instance in a VPC. If the command succeeds, no output is returned.

Command:

aws ec2 disassociate-address --association-id eipassoc-2bebb745

    public static void disassociateAddress(Ec2Client ec2, String associationId) {
        try {
            DisassociateAddressRequest addressRequest = DisassociateAddressRequest.builder()
                    .associationId(associationId)
                    .build();

            ec2.disassociateAddress(addressRequest);
            System.out.println("You successfully disassociated the address!");

        } catch (Ec2Exception e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

import { DisassociateAddressCommand } from "@aws-sdk/client-ec2";

import { client } from "../libs/client.js";

// Disassociate an Elastic IP address from an instance.
export const main = async () => {
  const command = new DisassociateAddressCommand({
    // You can also use PublicIp, but that is for EC2 classic which is being retired.
    AssociationId: "ASSOCIATION_ID",
  });

  try {
    await client.send(command);
    console.log("Successfully disassociated address");
  } catch (err) {
    console.error(err);
  }
};

suspend fun disassociateAddressSc(associationIdVal: String?) {
    val addressRequest =
        DisassociateAddressRequest {
            associationId = associationIdVal
        }
    Ec2Client { region = "us-west-2" }.use { ec2 ->
        ec2.disassociateAddress(addressRequest)
        println("You successfully disassociated the address!")
    }
}

Example 1: This example disassociates the specified Elastic IP address from the specified instance in a VPC.

Unregister-EC2Address -AssociationId eipassoc-12345678

Example 2: This example disassociates the specified Elastic IP address from the specified instance in EC2-Classic.

Unregister-EC2Address -PublicIp 203.0.113.17

class ElasticIpWrapper:
    """Encapsulates Amazon Elastic Compute Cloud (Amazon EC2) Elastic IP address actions."""

    def __init__(self, ec2_resource, elastic_ip=None):
        """
        :param ec2_resource: A Boto3 Amazon EC2 resource. This high-level resource
                             is used to create additional high-level objects
                             that wrap low-level Amazon EC2 service actions.
        :param elastic_ip: A Boto3 VpcAddress object. This is a high-level object that
                           wraps Elastic IP actions.
        """
        self.ec2_resource = ec2_resource
        self.elastic_ip = elastic_ip

    @classmethod
    def from_resource(cls):
        ec2_resource = boto3.resource("ec2")
        return cls(ec2_resource)


    def disassociate(self):
        """
        Removes an association between an Elastic IP address and an instance. When the
        association is removed, the instance is assigned a new public IP address.
        """
        if self.elastic_ip is None:
            logger.info("No Elastic IP to disassociate.")
            return

        try:
            self.elastic_ip.association.delete()
        except ClientError as err:
            logger.error(
                "Couldn't disassociate Elastic IP %s from its instance. Here's why: %s: %s",
                self.elastic_ip.allocation_id,
                err.response["Error"]["Code"],
                err.response["Error"]["Message"],
            )
            raise