diff --git a/include/osmocom/vlr/vlr.h b/include/osmocom/vlr/vlr.h
index ed6438bd0..b1994d038 100644
--- a/include/osmocom/vlr/vlr.h
+++ b/include/osmocom/vlr/vlr.h
@@ -204,6 +204,13 @@ enum vlr_ciph {
 	VLR_CIPH_A5_3 = 3, /*< A5/3, 'new secure' encryption */
 };
 
+enum vlr_inval_reason {
+	VLR_INVAL_REASON_WITHDRAWN, /*< HLR cancel location, reason subscription withdrawn */
+	VLR_INVAL_REASON_UPDATE_LOCATION, /*< HLR cancel location, reason update location */
+	VLR_INVAL_REASON_LOCATION_EXPIRED, /*< Location Update timer ran out */
+	VLR_INVAL_REASON_DUPLICATE_SUBSCR, /*< A newer record of the same subscriber exists. This is the old entry. */
+};
+
 static inline uint8_t vlr_ciph_to_gsm0808_alg_id(enum vlr_ciph ciph)
 {
 	switch (ciph) {
@@ -250,8 +257,8 @@ struct vlr_ops {
 	/* notify MSC/SGSN that the given subscriber has been associated
 	 * with this msc_conn_ref */
 	int (*subscr_assoc)(void *msc_conn_ref, struct vlr_subscr *vsub);
-	/* notify MSC that the given subscriber is no longer valid */
-	void (*subscr_inval)(void *msc_conn_ref, struct vlr_subscr *vsub);
+	/* notify MSC that the given subscriber is no longer valid. */
+	void (*subscr_inval)(void *msc_conn_ref, struct vlr_subscr *vsub, enum vlr_inval_reason reason);
 };
 
 /* An instance of the VLR codebase */
diff --git a/src/libmsc/gsm_04_08.c b/src/libmsc/gsm_04_08.c
index d9e0b5f42..de0a69373 100644
--- a/src/libmsc/gsm_04_08.c
+++ b/src/libmsc/gsm_04_08.c
@@ -1572,7 +1572,7 @@ static int msc_vlr_subscr_assoc(void *msc_conn_ref,
 	return 0;
 }
 
-static void msc_vlr_subscr_inval(void *msc_conn_ref, struct vlr_subscr *vsub)
+static void msc_vlr_subscr_inval(void *msc_conn_ref, struct vlr_subscr *vsub, enum vlr_inval_reason reason)
 {
 	/* Search vsub backwards to make sure msc_conn_ref is a valid msc_a instance. */
 	struct msub *msub;
diff --git a/src/libvlr/vlr.c b/src/libvlr/vlr.c
index 95b081a99..8e053ae03 100644
--- a/src/libvlr/vlr.c
+++ b/src/libvlr/vlr.c
@@ -629,7 +629,7 @@ static void dedup_vsub(struct vlr_subscr *exists, struct vlr_subscr *vsub)
 			 exists->imsi);
 
 	if (vlr->ops.subscr_inval)
-		vlr->ops.subscr_inval(exists->msc_conn_ref, exists);
+		vlr->ops.subscr_inval(exists->msc_conn_ref, exists, VLR_INVAL_REASON_DUPLICATE_SUBSCR);
 	vlr_subscr_free(exists);
 }