diff --git a/src/main/java/com/ffii/fpsms/modules/jobOrder/service/PlasticBagPrinterService.kt b/src/main/java/com/ffii/fpsms/modules/jobOrder/service/PlasticBagPrinterService.kt
index 33b6d49..d4a3834 100644
--- a/src/main/java/com/ffii/fpsms/modules/jobOrder/service/PlasticBagPrinterService.kt
+++ b/src/main/java/com/ffii/fpsms/modules/jobOrder/service/PlasticBagPrinterService.kt
@@ -161,8 +161,8 @@ class PlasticBagPrinterService(
                     .thenBy { it.jobOrderId },
             )
 
-        fun onPackExpiryFileStem(itemCodeLower: String, indexOneBased: Int): String =
-            "$itemCodeLower-$indexOneBased"
+        fun onPackExpiryFileStem(itemCodeLower: String, indexOneBased: Int, totalForItem: Int): String =
+            if (totalForItem > 1) "$itemCodeLower-$indexOneBased" else itemCodeLower
 
         /** ISO `yyyy-MM-dd`, compact `yyyyMMdd`, or already `Expiry Date yyyyMMdd`. */
         fun formatLaserExpiryParam(expiryDate: String?): String {
@@ -778,15 +778,22 @@ class PlasticBagPrinterService(
             .flatMap { (codeLower, orders) ->
                 val sorted = sortOnPackExportJobOrders(orders, jobOrdersById)
                 val selected = if (includeExpiry) sorted else listOfNotNull(sorted.firstOrNull())
-                selected.mapIndexedNotNull { index, order ->
+                val items = selected.mapNotNull { order ->
                     toOnPackBmpExportItem(
                         codeLower = codeLower,
-                        fileStem = if (includeExpiry) onPackExpiryFileStem(codeLower, index + 1) else codeLower,
+                        fileStem = codeLower,
                         order = order,
                         expiryPrintNames = expiryPrintNames,
                         jobOrder = jobOrdersById[order.jobOrderId],
                     )
                 }
+                if (includeExpiry) {
+                    items.mapIndexed { index, item ->
+                        item.copy(fileStem = onPackExpiryFileStem(codeLower, index + 1, items.size))
+                    }
+                } else {
+                    items
+                }
             }
 
         require(exportItemsRaw.isNotEmpty()) { "No OnPack QR files could be generated for the selected date" }
diff --git a/src/test/kotlin/com/ffii/fpsms/modules/jobOrder/service/OnPackExpiryZipStemTest.kt b/src/test/kotlin/com/ffii/fpsms/modules/jobOrder/service/OnPackExpiryZipStemTest.kt
index 0ec0a81..92da893 100644
--- a/src/test/kotlin/com/ffii/fpsms/modules/jobOrder/service/OnPackExpiryZipStemTest.kt
+++ b/src/test/kotlin/com/ffii/fpsms/modules/jobOrder/service/OnPackExpiryZipStemTest.kt
@@ -8,9 +8,10 @@ import org.junit.jupiter.api.Test
 class OnPackExpiryZipStemTest {
 
     @Test
-    fun expiry_file_stem_appends_one_based_index() {
-        assertEquals("pp2211-1", PlasticBagPrinterService.onPackExpiryFileStem("pp2211", 1))
-        assertEquals("pp2211-2", PlasticBagPrinterService.onPackExpiryFileStem("pp2211", 2))
+    fun expiry_file_stem_suffixes_only_when_item_has_more_than_one_job() {
+        assertEquals("pp2211", PlasticBagPrinterService.onPackExpiryFileStem("pp2211", 1, 1))
+        assertEquals("pp2211-1", PlasticBagPrinterService.onPackExpiryFileStem("pp2211", 1, 2))
+        assertEquals("pp2211-2", PlasticBagPrinterService.onPackExpiryFileStem("pp2211", 2, 2))
     }
 
     @Test