diff --git a/java/google/registry/flows/domain/flags/ExtensionFlagDomainPolicyErrorException.java b/java/google/registry/flows/domain/flags/ExtensionFlagDomainPolicyErrorException.java
new file mode 100644
index 000000000..2c95ea2af
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/ExtensionFlagDomainPolicyErrorException.java
@@ -0,0 +1,24 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.StatusProhibitsOperationException;
+
+/** Extension flag is not currently valid for this domain. */
+public class ExtensionFlagDomainPolicyErrorException extends StatusProhibitsOperationException {
+  public ExtensionFlagDomainPolicyErrorException(String flag) {
+    super(String.format("Extension flag %s is not valid for this domain", flag));
+  }
+}
diff --git a/java/google/registry/flows/domain/flags/ExtensionFlagMissingException.java b/java/google/registry/flows/domain/flags/ExtensionFlagMissingException.java
new file mode 100644
index 000000000..ca593b53e
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/ExtensionFlagMissingException.java
@@ -0,0 +1,28 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.RequiredParameterMissingException;
+
+/** Required extension flag missing. */
+public class ExtensionFlagMissingException extends RequiredParameterMissingException {
+  public ExtensionFlagMissingException(String flag) {
+    super(String.format("Flag %s must be specified", flag));
+  }
+
+  public ExtensionFlagMissingException(String flag1, String flag2) {
+    super(String.format("Either %s or %s must be specified", flag1, flag2));
+  }
+}
diff --git a/java/google/registry/flows/domain/flags/ExtensionFlagRegistrarPolicyErrorException.java b/java/google/registry/flows/domain/flags/ExtensionFlagRegistrarPolicyErrorException.java
new file mode 100644
index 000000000..933eaf16d
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/ExtensionFlagRegistrarPolicyErrorException.java
@@ -0,0 +1,24 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.ParameterValuePolicyErrorException;
+
+/** Extension flag is not currently valid for this registrar. */
+public class ExtensionFlagRegistrarPolicyErrorException extends ParameterValuePolicyErrorException {
+  public ExtensionFlagRegistrarPolicyErrorException(String flag) {
+    super(String.format("Extension flag %s is not valid for this registrar", flag));
+  }
+}
diff --git a/java/google/registry/flows/domain/flags/ExtensionFlagSetDomainPolicyErrorException.java b/java/google/registry/flows/domain/flags/ExtensionFlagSetDomainPolicyErrorException.java
new file mode 100644
index 000000000..1c53d8307
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/ExtensionFlagSetDomainPolicyErrorException.java
@@ -0,0 +1,24 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.StatusProhibitsOperationException;
+
+/** Extension flag cannot currently be set for this domain. */
+public class ExtensionFlagSetDomainPolicyErrorException extends StatusProhibitsOperationException {
+  public ExtensionFlagSetDomainPolicyErrorException(String flag) {
+    super(String.format("Extension flag %s cannot be set for this domain", flag));
+  }
+}
diff --git a/java/google/registry/flows/domain/flags/InvalidExtensionFlagException.java b/java/google/registry/flows/domain/flags/InvalidExtensionFlagException.java
new file mode 100644
index 000000000..abfcd3f0b
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/InvalidExtensionFlagException.java
@@ -0,0 +1,24 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.ParameterValueRangeErrorException;
+
+/** Extension flag is not valid. */
+public class InvalidExtensionFlagException extends ParameterValueRangeErrorException {
+  public InvalidExtensionFlagException(String flag) {
+    super(String.format("Extension flag %s is not defined", flag));
+  }
+}
diff --git a/java/google/registry/flows/domain/flags/MutuallyExclusiveExtensionFlagsException.java b/java/google/registry/flows/domain/flags/MutuallyExclusiveExtensionFlagsException.java
new file mode 100644
index 000000000..bd302969d
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/MutuallyExclusiveExtensionFlagsException.java
@@ -0,0 +1,24 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.ParameterValuePolicyErrorException;
+
+/** Specified extension flags are mutually exclusive. */
+public class MutuallyExclusiveExtensionFlagsException extends ParameterValuePolicyErrorException {
+  public MutuallyExclusiveExtensionFlagsException(String flag1, String flag2) {
+    super(String.format("Extension flags %s and %s are mutually exclusive", flag1, flag2));
+  }
+}
diff --git a/java/google/registry/flows/domain/flags/NonClientFlagException.java b/java/google/registry/flows/domain/flags/NonClientFlagException.java
new file mode 100644
index 000000000..f6c9a572e
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/NonClientFlagException.java
@@ -0,0 +1,24 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.ParameterValuePolicyErrorException;
+
+/** Only client flags can be updated. */
+public class NonClientFlagException extends ParameterValuePolicyErrorException {
+  public NonClientFlagException() {
+    super("Non-client flags cannot be added or removed");
+  }
+}
diff --git a/java/google/registry/flows/domain/flags/SameFlagAddedAndRemovedException.java b/java/google/registry/flows/domain/flags/SameFlagAddedAndRemovedException.java
new file mode 100644
index 000000000..b13f391f6
--- /dev/null
+++ b/java/google/registry/flows/domain/flags/SameFlagAddedAndRemovedException.java
@@ -0,0 +1,24 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.flows.domain.flags;
+
+import google.registry.flows.EppException.ParameterValuePolicyErrorException;
+
+/** The same flag was specified in both add and remove lists. */
+public class SameFlagAddedAndRemovedException extends ParameterValuePolicyErrorException {
+  public SameFlagAddedAndRemovedException() {
+    super("An extension flag cannot be both added and removed in the same command");
+  }
+}