diff --git a/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/tracker/CommandTracker.scala b/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/tracker/CommandTracker.scala
index 4d826d5009..e994a776d3 100644
--- a/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/tracker/CommandTracker.scala
+++ b/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/tracker/CommandTracker.scala
@@ -236,6 +236,11 @@ private[commands] class CommandTracker[Context](
         val submissionId = commands.submissionId
         val commandId = commands.commandId
         logger.trace(s"Begin tracking of command $commandId for submission $submissionId.")
+        if (commands.submissionId.isEmpty) {
+          throw new IllegalArgumentException(
+            s"The submission id for the command $commandId is empty. This should not happen."
+          )
+        }
         if (pendingCommands.contains(TrackedCommandKey(submissionId, commandId))) {
           // TODO return an error identical to the server side duplicate command error once that's defined.
           throw new IllegalStateException(
diff --git a/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/withoutledgerid/CommandClient.scala b/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/withoutledgerid/CommandClient.scala
index d37954f067..415cc2b921 100644
--- a/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/withoutledgerid/CommandClient.scala
+++ b/ledger/ledger-api-client/src/main/scala/com/digitalasset/ledger/client/services/commands/withoutledgerid/CommandClient.scala
@@ -8,6 +8,7 @@ import akka.stream.Materializer
 import akka.stream.scaladsl.{Flow, Keep, Sink, Source}
 import com.codahale.metrics.Counter
 import com.daml.grpc.adapter.ExecutionSequencerFactory
+import com.daml.ledger.api.SubmissionIdGenerator
 import com.daml.ledger.api.domain.LedgerId
 import com.daml.ledger.api.v1.command_completion_service.CommandCompletionServiceGrpc.CommandCompletionServiceStub
 import com.daml.ledger.api.v1.command_completion_service.{
@@ -64,6 +65,8 @@ private[daml] final class CommandClient(
       ],
     ]
 
+  private val submissionIdGenerator: SubmissionIdGenerator = SubmissionIdGenerator.Random
+
   /** Submit a single command. Successful result does not guarantee that the resulting transaction has been written to
     * the ledger. In order to get that semantic, use [[trackCommands]] or [[trackCommandsUnbounded]].
     */
@@ -198,10 +201,15 @@ private[daml] final class CommandClient(
           throw new IllegalArgumentException(
             s"Failing fast on submission request of command ${commands.commandId} with invalid ledger ID ${commands.ledgerId} (client expected $ledgerIdToUse)"
           )
-        else if (commands.applicationId != applicationId)
+        if (commands.applicationId != applicationId)
           throw new IllegalArgumentException(
             s"Failing fast on submission request of command ${commands.commandId} with invalid application ID ${commands.applicationId} (client expected $applicationId)"
           )
+        val nonEmptySubmissionId = if (commands.submissionId.isEmpty) {
+          submissionIdGenerator.generate()
+        } else {
+          commands.submissionId
+        }
         val updatedDeduplicationPeriod = commands.deduplicationPeriod match {
           case DeduplicationPeriod.Empty =>
             DeduplicationPeriod.DeduplicationTime(
@@ -213,7 +221,12 @@ private[daml] final class CommandClient(
             )
           case existing => existing
         }
-        submission.copy(commands = commands.copy(deduplicationPeriod = updatedDeduplicationPeriod))
+        submission.copy(commands =
+          commands.copy(
+            submissionId = nonEmptySubmissionId,
+            deduplicationPeriod = updatedDeduplicationPeriod,
+          )
+        )
       })
 
   def submissionFlow[Context](
diff --git a/ledger/ledger-api-client/src/test/suite/scala/com/digitalasset/ledger/client/services/commands/CommandTrackerFlowTest.scala b/ledger/ledger-api-client/src/test/suite/scala/com/digitalasset/ledger/client/services/commands/CommandTrackerFlowTest.scala
index 6f4a75aff2..9e9e9ea00a 100644
--- a/ledger/ledger-api-client/src/test/suite/scala/com/digitalasset/ledger/client/services/commands/CommandTrackerFlowTest.scala
+++ b/ledger/ledger-api-client/src/test/suite/scala/com/digitalasset/ledger/client/services/commands/CommandTrackerFlowTest.scala
@@ -152,6 +152,20 @@ class CommandTrackerFlowTest
       }
     }
 
+    "a command is submitted without a submission id" should {
+
+      "throw an exception" in {
+        val Handle(submissions, results, _, _) =
+          runCommandTrackingFlow(allSubmissionsSuccessful)
+
+        submissions.sendNext(newSubmission("", commandId))
+
+        val actualException = results.expectError()
+        actualException shouldBe an[IllegalArgumentException]
+        actualException.getMessage shouldBe s"The submission id for the command $commandId is empty. This should not happen."
+      }
+    }
+
     "the stream fails" should {
 
       "expose internal state as materialized value" in {
@@ -328,6 +342,7 @@ class CommandTrackerFlowTest
             CommandSubmission(
               Commands(
                 commandId = commandId,
+                submissionId = submissionId,
                 deduplicationPeriod =
                   Commands.DeduplicationPeriod.DeduplicationTime(deduplicationTime),
               )