diff --git a/moto/awslambda/models.py b/moto/awslambda/models.py
index 74fe3f151..a3e7f03ef 100644
--- a/moto/awslambda/models.py
+++ b/moto/awslambda/models.py
@@ -42,11 +42,10 @@ from .utils import make_function_arn, make_function_ver_arn
 from moto.sqs import sqs_backends
 from moto.dynamodb2 import dynamodb_backends2
 from moto.dynamodbstreams import dynamodbstreams_backends
+from moto.iam.models import ACCOUNT_ID
 
 logger = logging.getLogger(__name__)
 
-from moto.iam.models import ACCOUNT_ID
-
 
 try:
     from tempfile import TemporaryDirectory
diff --git a/moto/cloudformation/responses.py b/moto/cloudformation/responses.py
index 663183350..64481dd41 100644
--- a/moto/cloudformation/responses.py
+++ b/moto/cloudformation/responses.py
@@ -1056,7 +1056,7 @@ DESCRIBE_STACKSET_OPERATION_RESPONSE_TEMPLATE = """<DescribeStackSetOperationRes
   <DescribeStackSetOperationResult>
     <StackSetOperation>
       <ExecutionRoleName>{{ stackset.execution_role }}</ExecutionRoleName>
-      <AdministrationRoleARN>arn:aws:iam::"""+ACCOUNT_ID+""":role/{{ stackset.admin_role }}</AdministrationRoleARN>
+      <AdministrationRoleARN>arn:aws:iam::""" + ACCOUNT_ID + """:role/{{ stackset.admin_role }}</AdministrationRoleARN>
       <StackSetId>{{ stackset.id }}</StackSetId>
       <CreationTimestamp>{{ operation.CreationTimestamp }}</CreationTimestamp>
       <OperationId>{{ operation.OperationId }}</OperationId>
@@ -1081,7 +1081,7 @@ LIST_STACK_SET_OPERATION_RESULTS_RESPONSE_TEMPLATE = """<ListStackSetOperationRe
     {% for account, region in instance.items() %}
       <member>
         <AccountGateResult>
-          <StatusReason>Function not found: arn:aws:lambda:us-west-2:"""+ACCOUNT_ID+""":function:AWSCloudFormationStackSetAccountGate</StatusReason>
+          <StatusReason>Function not found: arn:aws:lambda:us-west-2:""" + ACCOUNT_ID + """:function:AWSCloudFormationStackSetAccountGate</StatusReason>
           <Status>SKIPPED</Status>
         </AccountGateResult>
         <Region>{{ region }}</Region>
diff --git a/moto/ec2/responses/instances.py b/moto/ec2/responses/instances.py
index 92654cfcc..32fa2e991 100644
--- a/moto/ec2/responses/instances.py
+++ b/moto/ec2/responses/instances.py
@@ -249,7 +249,7 @@ class InstanceResponse(BaseResponse):
 EC2_RUN_INSTANCES = """<RunInstancesResponse xmlns="http://ec2.amazonaws.com/doc/2013-10-15/">
   <requestId>59dbff89-35bd-4eac-99ed-be587EXAMPLE</requestId>
   <reservationId>{{ reservation.id }}</reservationId>
-  <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+  <ownerId>""" + ACCOUNT_ID + """</ownerId>
   <groupSet>
     <item>
       <groupId>sg-245f6a01</groupId>
@@ -331,7 +331,7 @@ EC2_RUN_INSTANCES = """<RunInstancesResponse xmlns="http://ec2.amazonaws.com/doc
                   <vpcId>{{ nic.subnet.vpc_id }}</vpcId>
                 {% endif %}
                 <description>Primary network interface</description>
-                <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+                <ownerId>""" + ACCOUNT_ID + """</ownerId>
                 <status>in-use</status>
                 <macAddress>1b:2b:3c:4d:5e:6f</macAddress>
                 <privateIpAddress>{{ nic.private_ip_address }}</privateIpAddress>
@@ -354,7 +354,7 @@ EC2_RUN_INSTANCES = """<RunInstancesResponse xmlns="http://ec2.amazonaws.com/doc
                 {% if nic.public_ip %}
                   <association>
                     <publicIp>{{ nic.public_ip }}</publicIp>
-                    <ipOwnerId>"""+ACCOUNT_ID+"""</ipOwnerId>
+                    <ipOwnerId>""" + ACCOUNT_ID + """</ipOwnerId>
                   </association>
                 {% endif %}
                 <privateIpAddressesSet>
@@ -364,7 +364,7 @@ EC2_RUN_INSTANCES = """<RunInstancesResponse xmlns="http://ec2.amazonaws.com/doc
                     {% if nic.public_ip %}
                       <association>
                         <publicIp>{{ nic.public_ip }}</publicIp>
-                        <ipOwnerId>"""+ACCOUNT_ID+"""</ipOwnerId>
+                        <ipOwnerId>""" + ACCOUNT_ID + """</ipOwnerId>
                       </association>
                     {% endif %}
                   </item>
@@ -383,7 +383,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns="http://ec2.amazona
         {% for reservation in reservations %}
           <item>
             <reservationId>{{ reservation.id }}</reservationId>
-            <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+            <ownerId>""" + ACCOUNT_ID + """</ownerId>
             <groupSet>
               {% for group in reservation.dynamic_group_list %}
               <item>
@@ -476,7 +476,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns="http://ec2.amazona
                      {% endfor %}
                     </blockDeviceMapping>
                     <virtualizationType>{{ instance.virtualization_type }}</virtualizationType>
-                    <clientToken>ABCDE"""+ACCOUNT_ID+"""3</clientToken>
+                    <clientToken>ABCDE""" + ACCOUNT_ID + """3</clientToken>
                     {% if instance.get_tags() %}
                     <tagSet>
                       {% for tag in instance.get_tags() %}
@@ -499,7 +499,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns="http://ec2.amazona
                             <vpcId>{{ nic.subnet.vpc_id }}</vpcId>
                           {% endif %}
                           <description>Primary network interface</description>
-                          <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+                          <ownerId>""" + ACCOUNT_ID + """</ownerId>
                           <status>in-use</status>
                           <macAddress>1b:2b:3c:4d:5e:6f</macAddress>
                           <privateIpAddress>{{ nic.private_ip_address }}</privateIpAddress>
@@ -526,7 +526,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns="http://ec2.amazona
                           {% if nic.public_ip %}
                             <association>
                               <publicIp>{{ nic.public_ip }}</publicIp>
-                              <ipOwnerId>"""+ACCOUNT_ID+"""</ipOwnerId>
+                              <ipOwnerId>""" + ACCOUNT_ID + """</ipOwnerId>
                             </association>
                           {% endif %}
                           <privateIpAddressesSet>
@@ -536,7 +536,7 @@ EC2_DESCRIBE_INSTANCES = """<DescribeInstancesResponse xmlns="http://ec2.amazona
                               {% if nic.public_ip %}
                                 <association>
                                   <publicIp>{{ nic.public_ip }}</publicIp>
-                                  <ipOwnerId>"""+ACCOUNT_ID+"""</ipOwnerId>
+                                  <ipOwnerId>""" + ACCOUNT_ID + """</ipOwnerId>
                                 </association>
                               {% endif %}
                             </item>
diff --git a/moto/ec2/responses/security_groups.py b/moto/ec2/responses/security_groups.py
index e90c4d5ff..e74dc7157 100644
--- a/moto/ec2/responses/security_groups.py
+++ b/moto/ec2/responses/security_groups.py
@@ -177,7 +177,7 @@ DESCRIBE_SECURITY_GROUPS_RESPONSE = """<DescribeSecurityGroupsResponse xmlns="ht
    <securityGroupInfo>
       {% for group in groups %}
           <item>
-             <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+             <ownerId>""" + ACCOUNT_ID + """</ownerId>
              <groupId>{{ group.id }}</groupId>
              <groupName>{{ group.name }}</groupName>
              <groupDescription>{{ group.description }}</groupDescription>
@@ -197,7 +197,7 @@ DESCRIBE_SECURITY_GROUPS_RESPONSE = """<DescribeSecurityGroupsResponse xmlns="ht
                        <groups>
                           {% for source_group in rule.source_groups %}
                               <item>
-                                 <userId>"""+ACCOUNT_ID+"""</userId>
+                                 <userId>""" + ACCOUNT_ID + """</userId>
                                  <groupId>{{ source_group.id }}</groupId>
                                  <groupName>{{ source_group.name }}</groupName>
                               </item>
@@ -226,7 +226,7 @@ DESCRIBE_SECURITY_GROUPS_RESPONSE = """<DescribeSecurityGroupsResponse xmlns="ht
                        <groups>
                           {% for source_group in rule.source_groups %}
                               <item>
-                                 <userId>"""+ACCOUNT_ID+"""</userId>
+                                 <userId>""" + ACCOUNT_ID + """</userId>
                                  <groupId>{{ source_group.id }}</groupId>
                                  <groupName>{{ source_group.name }}</groupName>
                               </item>
diff --git a/moto/ec2/responses/vpc_peering_connections.py b/moto/ec2/responses/vpc_peering_connections.py
index be1485488..df33ecf77 100644
--- a/moto/ec2/responses/vpc_peering_connections.py
+++ b/moto/ec2/responses/vpc_peering_connections.py
@@ -2,6 +2,7 @@ from __future__ import unicode_literals
 from moto.core.responses import BaseResponse
 from moto.iam.models import ACCOUNT_ID
 
+
 class VPCPeeringConnections(BaseResponse):
     def create_vpc_peering_connection(self):
         peer_region = self._get_param("PeerRegion")
@@ -56,7 +57,7 @@ CREATE_VPC_PEERING_CONNECTION_RESPONSE = """
      </peeringOptions>
     </requesterVpcInfo>
     <accepterVpcInfo>
-      <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+      <ownerId>""" + ACCOUNT_ID + """</ownerId>
       <vpcId>{{ vpc_pcx.peer_vpc.id }}</vpcId>
     </accepterVpcInfo>
     <status>
@@ -82,7 +83,7 @@ DESCRIBE_VPC_PEERING_CONNECTIONS_RESPONSE = """
      <cidrBlock>{{ vpc_pcx.vpc.cidr_block }}</cidrBlock>
     </requesterVpcInfo>
     <accepterVpcInfo>
-     <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+     <ownerId>""" + ACCOUNT_ID + """</ownerId>
      <vpcId>{{ vpc_pcx.peer_vpc.id }}</vpcId>
      <cidrBlock>{{ vpc_pcx.peer_vpc.cidr_block }}</cidrBlock>
      <peeringOptions>
@@ -120,7 +121,7 @@ ACCEPT_VPC_PEERING_CONNECTION_RESPONSE = """
       <cidrBlock>{{ vpc_pcx.vpc.cidr_block }}</cidrBlock>
     </requesterVpcInfo>
     <accepterVpcInfo>
-      <ownerId>"""+ACCOUNT_ID+"""</ownerId>
+      <ownerId>""" + ACCOUNT_ID + """</ownerId>
       <vpcId>{{ vpc_pcx.peer_vpc.id }}</vpcId>
       <cidrBlock>{{ vpc_pcx.peer_vpc.cidr_block }}</cidrBlock>
       <peeringOptions>
diff --git a/moto/iam/models.py b/moto/iam/models.py
index 272869e58..dd598c975 100644
--- a/moto/iam/models.py
+++ b/moto/iam/models.py
@@ -45,7 +45,7 @@ from .utils import (
     random_policy_id,
 )
 
-ACCOUNT_ID = '123456789012' #make sure this is a str and not an int
+ACCOUNT_ID = '123456789012'
 
 
 class MFADevice(object):
diff --git a/moto/organizations/utils.py b/moto/organizations/utils.py
index b33f219ff..0a685c629 100644
--- a/moto/organizations/utils.py
+++ b/moto/organizations/utils.py
@@ -2,8 +2,10 @@ from __future__ import unicode_literals
 
 import random
 import string
+from moto.iam.models import ACCOUNT_ID
 
-from moto.iam.models import ACCOUNT_ID as MASTER_ACCOUNT_ID
+
+MASTER_ACCOUNT_ID = ACCOUNT_ID
 MASTER_ACCOUNT_EMAIL = "master@example.com"
 DEFAULT_POLICY_ID = "p-FullAWSAccess"
 ORGANIZATION_ARN_FORMAT = "arn:aws:organizations::{0}:organization/{1}"
diff --git a/moto/s3/responses.py b/moto/s3/responses.py
index 7251314a3..ff3bec9cf 100644
--- a/moto/s3/responses.py
+++ b/moto/s3/responses.py
@@ -1899,7 +1899,7 @@ S3_ALL_MULTIPARTS = """<?xml version="1.0" encoding="UTF-8"?>
     <Key>{{ upload.key_name }}</Key>
     <UploadId>{{ upload.id }}</UploadId>
     <Initiator>
-      <ID>arn:aws:iam::"""+ACCOUNT_ID+""":user/user1-11111a31-17b5-4fb7-9df5-b111111f13de</ID>
+      <ID>arn:aws:iam::""" + ACCOUNT_ID + """:user/user1-11111a31-17b5-4fb7-9df5-b111111f13de</ID>
       <DisplayName>user1-11111a31-17b5-4fb7-9df5-b111111f13de</DisplayName>
     </Initiator>
     <Owner>