diff --git a/java/google/registry/ui/externs/json.js b/java/google/registry/ui/externs/json.js
index 33355f0fe..13d72b53f 100644
--- a/java/google/registry/ui/externs/json.js
+++ b/java/google/registry/ui/externs/json.js
@@ -77,7 +77,7 @@ registry.json.Response.prototype.results;
  *   ianaIdentifier: (number?|undefined),
  *   icannReferralEmail: string,
  *   ipAddressWhitelist: !Array<string>,
- *   emailAddress: string,
+ *   emailAddress: (string?|undefined),
  *   phonePasscode: (string?|undefined),
  *   phoneNumber: (string?|undefined),
  *   faxNumber: (string?|undefined),
diff --git a/java/google/registry/ui/server/RegistrarFormFields.java b/java/google/registry/ui/server/RegistrarFormFields.java
index 745b50988..3d288c426 100644
--- a/java/google/registry/ui/server/RegistrarFormFields.java
+++ b/java/google/registry/ui/server/RegistrarFormFields.java
@@ -71,12 +71,17 @@ public final class RegistrarFormFields {
           .required()
           .build();
 
-  public static final FormField<String, String> EMAIL_ADDRESS_FIELD =
+  public static final FormField<String, String> EMAIL_ADDRESS_FIELD_REQUIRED =
       FormFields.EMAIL.asBuilderNamed("emailAddress")
           .matches(ASCII_PATTERN, ASCII_ERROR)
           .required()
           .build();
 
+  public static final FormField<String, String> EMAIL_ADDRESS_FIELD_OPTIONAL =
+      FormFields.EMAIL.asBuilderNamed("emailAddress")
+          .matches(ASCII_PATTERN, ASCII_ERROR)
+          .build();
+
   public static final FormField<String, String> ICANN_REFERRAL_EMAIL_FIELD =
       FormFields.EMAIL.asBuilderNamed("icannReferralEmail")
           .matches(ASCII_PATTERN, ASCII_ERROR)
diff --git a/java/google/registry/ui/server/registrar/RegistrarSettingsAction.java b/java/google/registry/ui/server/registrar/RegistrarSettingsAction.java
index 24cefa3f1..f85c94853 100644
--- a/java/google/registry/ui/server/registrar/RegistrarSettingsAction.java
+++ b/java/google/registry/ui/server/registrar/RegistrarSettingsAction.java
@@ -20,6 +20,7 @@ import static google.registry.model.ofy.ObjectifyService.ofy;
 import static google.registry.security.JsonResponseHelper.Status.ERROR;
 import static google.registry.security.JsonResponseHelper.Status.SUCCESS;
 
+import com.google.common.base.Strings;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -125,14 +126,14 @@ public class RegistrarSettingsAction implements Runnable, JsonActionRunner.JsonA
           initialRegistrar.getClientId(),
           args);
       return JsonResponseHelper.createFormFieldError(e.getMessage(), e.getFieldName());
-    } catch (FormException ee) {
+    } catch (FormException e) {
       logger.warningfmt(
-          ee,
+          e,
           "Failed to perform operation '%s' on registrar '%s' for args %s",
           op,
           initialRegistrar.getClientId(),
           args);
-      return JsonResponseHelper.create(ERROR, ee.getMessage());
+      return JsonResponseHelper.create(ERROR, e.getMessage());
     }
 
   }
@@ -196,7 +197,12 @@ public class RegistrarSettingsAction implements Runnable, JsonActionRunner.JsonA
         RegistrarFormFields.WHOIS_SERVER_FIELD.extractUntyped(args).orElse(null));
     builder.setReferralUrl(
         RegistrarFormFields.REFERRAL_URL_FIELD.extractUntyped(args).orElse(null));
-    RegistrarFormFields.EMAIL_ADDRESS_FIELD
+
+    // If the email is already null / empty - we can keep it so. But if it's set - it's required to
+    // remain set.
+    (Strings.isNullOrEmpty(existingRegistrarObj.getEmailAddress())
+            ? RegistrarFormFields.EMAIL_ADDRESS_FIELD_OPTIONAL
+            : RegistrarFormFields.EMAIL_ADDRESS_FIELD_REQUIRED)
         .extractUntyped(args)
         .ifPresent(builder::setEmailAddress);
     builder.setPhoneNumber(
diff --git a/java/google/registry/ui/soy/registrar/WhoisSettings.soy b/java/google/registry/ui/soy/registrar/WhoisSettings.soy
index 620a264ec..3b9d77667 100644
--- a/java/google/registry/ui/soy/registrar/WhoisSettings.soy
+++ b/java/google/registry/ui/soy/registrar/WhoisSettings.soy
@@ -25,7 +25,7 @@
   {@param? whoisServer: string}
   {@param? referralUrl: string}
   // Passed to .contactInfo_
-  {@param emailAddress: string}
+  {@param? emailAddress: string}
   {@param? localizedAddress: ?}
   {@param? phoneNumber: string}
   {@param? faxNumber: string}
@@ -79,7 +79,7 @@
  * Contact info.
  */
 {template .contactInfo_ visibility="private"}
-  {@param emailAddress: string}
+  {@param? emailAddress: string}
   {@param readonly: bool}
   {@param? localizedAddress: ?}
   {@param? phoneNumber: string}
@@ -107,11 +107,13 @@
                  value="{$faxNumber}">
           <div class="{css('contact-fax-number')}">{$faxNumber} (Fax)</div>
         {/if}
-        <input type="hidden"
-               name="emailAddress"
-               id="emailAddress"
-               value="{$emailAddress}">
-        <div class="{css('contact-fax-number')}">{$emailAddress}</div>
+        {if isNonnull($emailAddress)}
+          <input type="hidden"
+                 name="emailAddress"
+                 id="emailAddress"
+                 value="{$emailAddress}">
+          <div class="{css('contact-fax-number')}">{$emailAddress}</div>
+        {/if}
       </td>
   {else}
     {call registry.soy.forms.inputFieldRowWithValue}
diff --git a/javatests/google/registry/server/RegistryTestServer.java b/javatests/google/registry/server/RegistryTestServer.java
index 911eb7a52..4cf4c95fb 100644
--- a/javatests/google/registry/server/RegistryTestServer.java
+++ b/javatests/google/registry/server/RegistryTestServer.java
@@ -88,6 +88,8 @@ public final class RegistryTestServer {
       route("/registrar", google.registry.module.frontend.FrontendServlet.class),
       route("/registrar-settings",
           google.registry.module.frontend.FrontendServlet.class),
+      route("/registrar-premium-price-ack",
+          google.registry.module.frontend.FrontendServlet.class),
       route("/registrar-payment",
           google.registry.module.frontend.FrontendServlet.class),
       route("/registrar-payment-setup",
diff --git a/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTest.java b/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTest.java
index b1a639883..650158cdc 100644
--- a/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTest.java
+++ b/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTest.java
@@ -16,6 +16,7 @@ package google.registry.ui.server.registrar;
 
 import static com.google.common.truth.Truth.assertThat;
 import static google.registry.testing.DatastoreHelper.loadRegistrar;
+import static google.registry.testing.DatastoreHelper.persistResource;
 import static google.registry.testing.JUnitBackports.assertThrows;
 import static google.registry.testing.TaskQueueHelper.assertNoTasksEnqueued;
 import static google.registry.testing.TaskQueueHelper.assertTasksEnqueued;
@@ -98,6 +99,16 @@ public class RegistrarSettingsActionTest extends RegistrarSettingsActionTestCase
     assertNoTasksEnqueued("sheet");
   }
 
+  @Test
+  public void testUpdate_emptyJsonObject_emailFieldNotRequiredWhenEmpty() throws Exception {
+    persistResource(loadRegistrar(CLIENT_ID).asBuilder().setEmailAddress(null).build());
+
+    Map<String, Object> response = action.handleJsonRequest(ImmutableMap.of(
+        "op", "update",
+        "args", ImmutableMap.of()));
+    assertThat(response).containsEntry("status", "SUCCESS");
+  }
+
   @Test
   public void testUpdate_badEmail_errorEmailField() throws Exception {
     Map<String, Object> response = action.handleJsonRequest(ImmutableMap.of(
diff --git a/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTestCase.java b/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTestCase.java
index 433fc5fd5..b10c325d0 100644
--- a/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTestCase.java
+++ b/javatests/google/registry/ui/server/registrar/RegistrarSettingsActionTestCase.java
@@ -106,8 +106,12 @@ public class RegistrarSettingsActionTestCase {
     when(rsp.getWriter()).thenReturn(new PrintWriter(writer));
     when(req.getContentType()).thenReturn("application/json");
     when(req.getReader()).thenReturn(createJsonPayload(ImmutableMap.of("op", "read")));
+    // We mock getRegistrarForAuthResult to reload the registrar each time it's called. Otherwise -
+    // the result is out of date after mutations.
+    // (for example, if someone wants to change the registrar to prepare for a test, the function
+    // would still return the old value)
     when(sessionUtils.getRegistrarForAuthResult(req, action.authResult))
-        .thenReturn(loadRegistrar(CLIENT_ID));
+        .thenAnswer(x -> loadRegistrar(CLIENT_ID));
     when(modulesService.getVersionHostname("backend", null)).thenReturn("backend.hostname");
   }