diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index e63e0be..53993b2 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -612,7 +612,9 @@
 existing accounts this username is already in lower case. It is not
 possible to convert the usernames of the existing accounts to lower
 case because this would break the access to existing per-user
-branches and Gerrit provides no tool to do such a conversion.
+branches and Gerrit provides no tool to do such a conversion. Accounts
+created using the REST API or the `create-account` SSH command will
+be created with all lowercase characters, when this option is set.
 +
 Setting this parameter to `true` will prevent all users from login that
 have a non-lower-case username.
diff --git a/java/com/google/gerrit/server/restapi/account/CreateAccount.java b/java/com/google/gerrit/server/restapi/account/CreateAccount.java
index c110194..6ad6d97 100644
--- a/java/com/google/gerrit/server/restapi/account/CreateAccount.java
+++ b/java/com/google/gerrit/server/restapi/account/CreateAccount.java
@@ -44,6 +44,7 @@
 import com.google.gerrit.server.account.VersionedAuthorizedKeys;
 import com.google.gerrit.server.account.externalids.DuplicateExternalIdKeyException;
 import com.google.gerrit.server.account.externalids.ExternalId;
+import com.google.gerrit.server.config.AuthConfig;
 import com.google.gerrit.server.group.GroupResolver;
 import com.google.gerrit.server.group.db.GroupsUpdate;
 import com.google.gerrit.server.group.db.InternalGroupUpdate;
@@ -59,6 +60,7 @@
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Set;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 
@@ -75,6 +77,7 @@
   private final PluginSetContext<AccountExternalIdCreator> externalIdCreators;
   private final Provider<GroupsUpdate> groupsUpdate;
   private final OutgoingEmailValidator validator;
+  private final AuthConfig authConfig;
 
   @Inject
   CreateAccount(
@@ -86,7 +89,8 @@
       AccountLoader.Factory infoLoader,
       PluginSetContext<AccountExternalIdCreator> externalIdCreators,
       @UserInitiated Provider<GroupsUpdate> groupsUpdate,
-      OutgoingEmailValidator validator) {
+      OutgoingEmailValidator validator,
+      AuthConfig authConfig) {
     this.seq = seq;
     this.groupResolver = groupResolver;
     this.authorizedKeys = authorizedKeys;
@@ -96,6 +100,7 @@
     this.externalIdCreators = externalIdCreators;
     this.groupsUpdate = groupsUpdate;
     this.validator = validator;
+    this.authConfig = authConfig;
   }
 
   @Override
@@ -109,14 +114,18 @@
   public Response<AccountInfo> apply(IdString id, AccountInput input)
       throws BadRequestException, ResourceConflictException, UnprocessableEntityException,
           IOException, ConfigInvalidException, PermissionBackendException {
-    String username = id.get();
-    if (input.username != null && !username.equals(input.username)) {
+    String username = applyCaseOfUsername(id.get());
+    if (input.username != null && !username.equals(applyCaseOfUsername(input.username))) {
       throw new BadRequestException("username must match URL");
     }
     if (!ExternalId.isValidUsername(username)) {
       throw new BadRequestException("Invalid username '" + username + "'");
     }
 
+    if (input.name == null) {
+      input.name = input.username;
+    }
+
     Set<AccountGroup.UUID> groups = parseGroups(input.groups);
 
     Account.Id accountId = Account.id(seq.nextAccountId());
@@ -175,6 +184,10 @@
     return Response.created(info);
   }
 
+  private String applyCaseOfUsername(String username) {
+    return authConfig.isUserNameToLowerCase() ? username.toLowerCase(Locale.US) : username;
+  }
+
   private Set<AccountGroup.UUID> parseGroups(List<String> groups)
       throws UnprocessableEntityException {
     Set<AccountGroup.UUID> groupUuids = new HashSet<>();
diff --git a/javatests/com/google/gerrit/acceptance/rest/account/CreateAccountIT.java b/javatests/com/google/gerrit/acceptance/rest/account/CreateAccountIT.java
index aca6c4c..1b83d92 100644
--- a/javatests/com/google/gerrit/acceptance/rest/account/CreateAccountIT.java
+++ b/javatests/com/google/gerrit/acceptance/rest/account/CreateAccountIT.java
@@ -17,6 +17,7 @@
 import static com.google.common.truth.Truth8.assertThat;
 
 import com.google.gerrit.acceptance.AbstractDaemonTest;
+import com.google.gerrit.acceptance.GerritConfig;
 import com.google.gerrit.acceptance.RestResponse;
 import com.google.gerrit.extensions.api.accounts.AccountInput;
 import org.junit.Test;
@@ -31,4 +32,44 @@
     r.assertCreated();
     assertThat(accountCache.getByUsername(input.username)).isPresent();
   }
+
+  @Test
+  @GerritConfig(name = "auth.userNameToLowerCase", value = "false")
+  public void createAccountRestApiUserNameToLowerCaseFalse() throws Exception {
+    AccountInput input = new AccountInput();
+    input.username = "JohnDoe";
+    assertThat(accountCache.getByUsername(input.username)).isEmpty();
+    RestResponse r = adminRestSession.put("/accounts/" + input.username, input);
+    r.assertCreated();
+    assertThat(accountCache.getByUsername(input.username)).isPresent();
+  }
+
+  @Test
+  @GerritConfig(name = "auth.userNameToLowerCase", value = "true")
+  public void createAccountRestApiUserNameToLowerCaseTrue() throws Exception {
+    testUserNameToLowerCase("John1", "John1", "john1");
+    assertThat(accountCache.getByUsername("John1")).isEmpty();
+
+    testUserNameToLowerCase("john2", "John2", "john2");
+    assertThat(accountCache.getByUsername("John2")).isEmpty();
+
+    testUserNameToLowerCase("John3", "john3", "john3");
+    assertThat(accountCache.getByUsername("John3")).isEmpty();
+
+    testUserNameToLowerCase("John4", "johN4", "john4");
+    assertThat(accountCache.getByUsername("John4")).isEmpty();
+    assertThat(accountCache.getByUsername("johN4")).isEmpty();
+
+    testUserNameToLowerCase("john5", "john5", "john5");
+  }
+
+  private void testUserNameToLowerCase(String usernameUrl, String usernameInput, String usernameDb)
+      throws Exception {
+    AccountInput input = new AccountInput();
+    input.username = usernameInput;
+    assertThat(accountCache.getByUsername(usernameDb)).isEmpty();
+    RestResponse r = adminRestSession.put("/accounts/" + usernameUrl, input);
+    r.assertCreated();
+    assertThat(accountCache.getByUsername(usernameDb)).isPresent();
+  }
 }