diff --git a/core/src/main/java/google/registry/persistence/transaction/IdService.java b/core/src/main/java/google/registry/persistence/transaction/IdService.java
deleted file mode 100644
index 77797789c66..00000000000
--- a/core/src/main/java/google/registry/persistence/transaction/IdService.java
+++ /dev/null
@@ -1,42 +0,0 @@
-// Copyright 2021 The Nomulus 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.persistence.transaction;
-
-import static google.registry.persistence.transaction.TransactionManagerFactory.tm;
-
-import java.util.concurrent.atomic.AtomicLong;
-
-/**
- * Allocates a {@code long} to use as a {@code @Id}, (part) of the primary SQL key for an entity.
- */
-final class IdService {
-
-  private IdService() {}
-
-  /**
-   * A SQL Sequence based ID allocator that generates an ID from a monotonically increasing {@link
-   * AtomicLong}
-   *
-   * <p>The generated IDs are project-wide unique.
-   */
-  static long allocateId() {
-    return tm().transact(
-            () ->
-                (Long)
-                    tm().getEntityManager()
-                        .createNativeQuery("SELECT nextval('project_wide_unique_id_seq')")
-                        .getSingleResult());
-  }
-}
diff --git a/core/src/main/java/google/registry/persistence/transaction/JpaTransactionManagerImpl.java b/core/src/main/java/google/registry/persistence/transaction/JpaTransactionManagerImpl.java
index 8409b00aa32..f693630ea0d 100644
--- a/core/src/main/java/google/registry/persistence/transaction/JpaTransactionManagerImpl.java
+++ b/core/src/main/java/google/registry/persistence/transaction/JpaTransactionManagerImpl.java
@@ -70,6 +70,7 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.Callable;
+import java.util.concurrent.atomic.AtomicLong;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
@@ -224,7 +225,7 @@ public <T> T transactNoRetry(
     EntityTransaction txn = txnInfo.entityManager.getTransaction();
     try {
       txn.begin();
-      txnInfo.start(clock, readOnly ? ReplicaDbIdService::allocatedId : IdService::allocateId);
+      txnInfo.start(clock, readOnly ? ReplicaDbIdService::allocateId : this::fetchIdFromSequence);
       if (readOnly) {
         getEntityManager().createNativeQuery("SET TRANSACTION READ ONLY").executeUpdate();
         logger.atInfo().log("Using read-only SQL replica");
@@ -558,6 +559,19 @@ private <T> EntityType<T> getEntityType(Class<T> clazz) {
     return emf.getMetamodel().entity(clazz);
   }
 
+  /**
+   * A SQL Sequence based ID allocator that generates an ID from a monotonically increasing {@link
+   * AtomicLong}
+   *
+   * <p>The generated IDs are project-wide unique.
+   */
+  private long fetchIdFromSequence() {
+    return (Long)
+        getEntityManager()
+            .createNativeQuery("SELECT nextval('project_wide_unique_id_seq')")
+            .getSingleResult();
+  }
+
   private record EntityId(String name, Object value) {}
 
   private static ImmutableSet<EntityId> getEntityIdsFromEntity(
@@ -1038,4 +1052,23 @@ public ImmutableList<T> list() {
           .collect(toImmutableList());
     }
   }
+
+  /**
+   * Provides {@code long} values for use as {@code id} by JPA model entities in (read-only)
+   * transactions in the replica database. Each id is only unique in the JVM instance.
+   *
+   * <p>The {@link #fetchIdFromSequence database sequence-based id allocator} cannot be used with
+   * the replica because id generation is a write operation.
+   */
+  private static final class ReplicaDbIdService {
+
+    private static final AtomicLong nextId = new AtomicLong(1);
+
+    /**
+     * Returns the next long value from a {@link AtomicLong}. Each id is unique in the JVM instance.
+     */
+    static long allocateId() {
+      return nextId.getAndIncrement();
+    }
+  }
 }
diff --git a/core/src/main/java/google/registry/persistence/transaction/ReplicaDbIdService.java b/core/src/main/java/google/registry/persistence/transaction/ReplicaDbIdService.java
deleted file mode 100644
index 30a99d674f8..00000000000
--- a/core/src/main/java/google/registry/persistence/transaction/ReplicaDbIdService.java
+++ /dev/null
@@ -1,38 +0,0 @@
-// Copyright 2024 The Nomulus 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.persistence.transaction;
-
-import java.util.concurrent.atomic.AtomicLong;
-
-/**
- * Provides {@code long} values for use as {@code id} by JPA model entities in (read-only)
- * transactions in the replica database. Each id is only unique in the JVM instance.
- *
- * <p>The {@link IdService database sequence-based id service} cannot be used with the replica
- * because id generation is a write operation.
- */
-final class ReplicaDbIdService {
-
-  private ReplicaDbIdService() {}
-
-  private static final AtomicLong nextId = new AtomicLong(1);
-
-  /**
-   * Returns the next long value from a {@link AtomicLong}. Each id is unique in the JVM instance.
-   */
-  static final long allocatedId() {
-    return nextId.getAndIncrement();
-  }
-}