diff --git a/processor/processor.go b/processor/processor.go
index 6b65d73395..f25f66bf8e 100644
--- a/processor/processor.go
+++ b/processor/processor.go
@@ -961,6 +961,7 @@ func (proc *Handle) makeCommonMetadataFromSingularEvent(singularEvent types.Sing
 	commonMetadata := transformer.Metadata{}
 	commonMetadata.SourceID = source.ID
 	commonMetadata.SourceName = source.Name
+	commonMetadata.OriginalSourceID = source.OriginalID
 	commonMetadata.WorkspaceID = source.WorkspaceID
 	commonMetadata.Namespace = proc.namespace
 	commonMetadata.InstanceID = proc.instanceID
@@ -992,6 +993,7 @@ func enhanceWithMetadata(commonMetadata *transformer.Metadata, event *transforme
 	metadata.SourceType = commonMetadata.SourceType
 	metadata.SourceCategory = commonMetadata.SourceCategory
 	metadata.SourceID = commonMetadata.SourceID
+	metadata.OriginalSourceID = commonMetadata.OriginalSourceID
 	metadata.SourceName = commonMetadata.SourceName
 	metadata.WorkspaceID = commonMetadata.WorkspaceID
 	metadata.Namespace = commonMetadata.Namespace
@@ -2495,6 +2497,7 @@ func (proc *Handle) transformSrcDest(
 	commonMetaData := &transformer.Metadata{
 		SourceID:             sourceID,
 		SourceName:           sourceName,
+		OriginalSourceID:     eventList[0].Metadata.OriginalSourceID,
 		SourceType:           eventList[0].Metadata.SourceType,
 		SourceCategory:       eventList[0].Metadata.SourceCategory,
 		WorkspaceID:          workspaceID,
diff --git a/processor/transformer/transformer.go b/processor/transformer/transformer.go
index adbed020a2..d46fdc8611 100644
--- a/processor/transformer/transformer.go
+++ b/processor/transformer/transformer.go
@@ -47,6 +47,7 @@ var json = jsoniter.ConfigCompatibleWithStandardLibrary
 type Metadata struct {
 	SourceID            string                            `json:"sourceId"`
 	SourceName          string                            `json:"sourceName"`
+	OriginalSourceID    string                            `json:"originalSourceId"`
 	WorkspaceID         string                            `json:"workspaceId"`
 	Namespace           string                            `json:"namespace"`
 	InstanceID          string                            `json:"instanceId"`
@@ -248,6 +249,15 @@ func (trans *handle) transform(
 	if len(clientEvents) == 0 {
 		return Response{}
 	}
+	// flip sourceID and originalSourceID if it's a replay source for the purpose of any user transformation
+	// flip back afterwards
+	for _, clientEvent := range clientEvents {
+		if clientEvent.Metadata.OriginalSourceID != "" {
+			originalSourceID := clientEvent.Metadata.OriginalSourceID
+			clientEvent.Metadata.OriginalSourceID = clientEvent.Metadata.SourceID
+			clientEvent.Metadata.SourceID = originalSourceID
+		}
+	}
 	sTags := stats.Tags{
 		"dest_type": clientEvents[0].Destination.DestinationDefinition.Name,
 		"dest_id":   clientEvents[0].Destination.ID,
@@ -306,6 +316,11 @@ func (trans *handle) transform(
 		// Transform is one to many mapping so returned
 		// response for each is an array. We flatten it out
 		for _, transformerResponse := range batch {
+			if transformerResponse.Metadata.OriginalSourceID != "" {
+				originalSourceID := transformerResponse.Metadata.SourceID
+				transformerResponse.Metadata.SourceID = transformerResponse.Metadata.OriginalSourceID
+				transformerResponse.Metadata.OriginalSourceID = originalSourceID
+			}
 			switch transformerResponse.StatusCode {
 			case http.StatusOK:
 				outClientEvents = append(outClientEvents, transformerResponse)