diff --git a/src/main/kotlin/com/restapi/controllers/Entities.kt b/src/main/kotlin/com/restapi/controllers/Entities.kt
index fa3e11b..b0837e8 100644
--- a/src/main/kotlin/com/restapi/controllers/Entities.kt
+++ b/src/main/kotlin/com/restapi/controllers/Entities.kt
@@ -851,11 +851,20 @@ object IncomingInventoryCtrl {
 
     fun getNextNum(ctx: Context) {
         val prefix = "MRN/"
+        val plantId = ctx.queryParam("plantId") ?: throw BadRequestResponse("plantId not sent")
+        val plant = database.find(Plant::class.java)
+            .where()
+            .eq("plantId", plantId)
+            .findOne() ?: throw BadRequestResponse("plant missing for $plantId")
+        val inventoryPrefix = plant.prefixes?.get("INBOUND") ?: prefix
+
         val cnt = (database.find(IncomingInventory::class.java)
+            .where()
+            .eq("unloadingPlantId", plantId)
             .findCount() + 1)
             .toString()
             .padStart(6, '0')
-        val seq = SequenceNumber(prefix + cnt)
+        val seq = SequenceNumber(inventoryPrefix + cnt)
         ctx.json(seq).status(HttpStatus.OK)
     }
 }
diff --git a/src/main/kotlin/com/restapi/domain/models.kt b/src/main/kotlin/com/restapi/domain/models.kt
index 4d65e75..163e563 100644
--- a/src/main/kotlin/com/restapi/domain/models.kt
+++ b/src/main/kotlin/com/restapi/domain/models.kt
@@ -434,11 +434,13 @@ open class IncomingInventory : BaseTenantModel() {
         this.vendor = updated.vendor
         this.loading = updated.loading
         this.unloading = updated.unloading
+        this.unloadingPlantId = updated.unloadingPlantId
     }
 
     var mrn: String? = null
     var date: LocalDate? = null
     var vendorBillNum: String? = null
+    var unloadingPlantId: String? = null
     var vendorBillAmount: Double = 0.0
     var vehicle: String = ""
     var loading: String? = ""
@@ -659,4 +661,6 @@ open class ReminderLog : BaseTenantModel() {
 open class Plant : BaseModel() {
     var plantId: String = ""
     var plantName: String = ""
+    @DbJsonB
+    var prefixes: Map<String,String>? = emptyMap()
 }
\ No newline at end of file
diff --git a/src/main/resources/dbmigration/1.28.sql b/src/main/resources/dbmigration/1.28.sql
new file mode 100644
index 0000000..b85bfc2
--- /dev/null
+++ b/src/main/resources/dbmigration/1.28.sql
@@ -0,0 +1,2 @@
+-- apply alter tables
+alter table incoming_inventory add column if not exists unloading_plant_id varchar(255);
diff --git a/src/main/resources/dbmigration/1.29.sql b/src/main/resources/dbmigration/1.29.sql
new file mode 100644
index 0000000..151db0e
--- /dev/null
+++ b/src/main/resources/dbmigration/1.29.sql
@@ -0,0 +1,2 @@
+-- apply alter tables
+alter table plant add column if not exists prefixes jsonb;
diff --git a/src/main/resources/dbmigration/model/1.28.model.xml b/src/main/resources/dbmigration/model/1.28.model.xml
new file mode 100644
index 0000000..9c4ac34
--- /dev/null
+++ b/src/main/resources/dbmigration/model/1.28.model.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<migration xmlns="http://ebean-orm.github.io/xml/ns/dbmigration">
+    <changeSet type="apply">
+        <addColumn tableName="incoming_inventory">
+            <column name="unloading_plant_id" type="varchar"/>
+        </addColumn>
+    </changeSet>
+</migration>
\ No newline at end of file
diff --git a/src/main/resources/dbmigration/model/1.29.model.xml b/src/main/resources/dbmigration/model/1.29.model.xml
new file mode 100644
index 0000000..4f5b569
--- /dev/null
+++ b/src/main/resources/dbmigration/model/1.29.model.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<migration xmlns="http://ebean-orm.github.io/xml/ns/dbmigration">
+    <changeSet type="apply">
+        <addColumn tableName="plant">
+            <column name="prefixes" type="jsonb"/>
+        </addColumn>
+    </changeSet>
+</migration>
\ No newline at end of file