diff --git a/src/main/java/org/mtransit/android/commons/provider/GTFSRealTimeProvider.java b/src/main/java/org/mtransit/android/commons/provider/GTFSRealTimeProvider.java
index 4c9f0ae3..e6caabdd 100644
--- a/src/main/java/org/mtransit/android/commons/provider/GTFSRealTimeProvider.java
+++ b/src/main/java/org/mtransit/android/commons/provider/GTFSRealTimeProvider.java
@@ -442,6 +442,20 @@ public static boolean isIGNORE_DIRECTION(@NonNull Context context) {
 		return ignoreDirection;
 	}
 
+	@Nullable
+	private static String agencyIdCleanupRegex = null;
+
+	/**
+	 * Override if multiple {@link GTFSRealTimeProvider} implementations in same app.
+	 */
+	@NonNull
+	private static String getAGENCY_ID_CLEANUP_REGEX(@NonNull Context context) {
+		if (agencyIdCleanupRegex == null) {
+			agencyIdCleanupRegex = context.getResources().getString(R.string.gtfs_rts_agency_id_cleanup_regex); // do not change to avoid breaking compat w/ old modules
+		}
+		return agencyIdCleanupRegex;
+	}
+
 	@Nullable
 	private static String serviceIdCleanupRegex = null;
 
@@ -1005,14 +1019,12 @@ private HashSet<ServiceUpdate> processAlerts(
 		for (GtfsRealtime.EntitySelector gInformedEntity : gInformedEntityList) {
 			if (gInformedEntity.hasAgencyId()
 					&& !providerAgencyId.isEmpty()
-					&& !providerAgencyId.equals(gInformedEntity.getAgencyId())) {
-				MTLog.w(this, "processAlerts() > Alert targets another agency: %s", gInformedEntity.getAgencyId());
+					&& !providerAgencyId.equals(GTFSRealTimeProviderExtKt.parseAgencyId(this, gInformedEntity))) {
+				MTLog.w(this, "processAlerts() > Alert targets another agency: '%s'!", gInformedEntity.getAgencyId());
 				continue;
 			}
 			final String targetUUID = GTFSRealTimeServiceAlertsProvider.parseProviderTargetUUID(this, gInformedEntity, ignoreDirection);
-			if (targetUUID == null || targetUUID.isEmpty()) {
-				continue;
-			}
+			if (targetUUID == null || targetUUID.isEmpty()) continue;
 			final String targetTripId = !FeatureFlags.F_USE_TRIP_IS_FOR_SERVICE_UPDATES ? null : GTFSRealTimeServiceAlertsProvider.parseTargetTripId(this, gInformedEntity);
 			targetUUIDAndTripId.put(targetUUID, targetTripId);
 			final int severity = GTFSRTAlertsManager.parseSeverity(gInformedEntity, gEffect);
@@ -1288,12 +1300,26 @@ private ArrayMap<String, String> parseTranslations(@NonNull GtfsRealtime.Transla
 		return translations;
 	}
 
+	@Nullable
+	private Pattern agencyIdCleanupPattern = null;
+
+	private boolean agencyIdCleanupPatternSet = false;
+
+	@Nullable
+	public Pattern getAgencyIdCleanupPattern(@NonNull Context context) {
+		if (this.agencyIdCleanupPattern == null && !agencyIdCleanupPatternSet) {
+			this.agencyIdCleanupPattern = GTFSCommons.makeIdCleanupPattern(getAGENCY_ID_CLEANUP_REGEX(context));
+			this.agencyIdCleanupPatternSet = true;
+		}
+		return this.agencyIdCleanupPattern;
+	}
+
 	@Nullable
 	private Pattern serviceIdCleanupPattern = null;
 
 	private boolean serviceIdCleanupPatternSet = false;
 
-	@SuppressWarnings("unused") // TODO use later for trip_updates, vehicle_location...
+	@SuppressWarnings("unused")
 	@Nullable
 	private Pattern getServiceIdCleanupPattern(@NonNull Context context) {
 		if (this.serviceIdCleanupPattern == null && !serviceIdCleanupPatternSet) {
diff --git a/src/main/java/org/mtransit/android/commons/provider/gtfs/GTFSRealTimeProviderExt.kt b/src/main/java/org/mtransit/android/commons/provider/gtfs/GTFSRealTimeProviderExt.kt
index c8299e1c..5f89f0ec 100644
--- a/src/main/java/org/mtransit/android/commons/provider/gtfs/GTFSRealTimeProviderExt.kt
+++ b/src/main/java/org/mtransit/android/commons/provider/gtfs/GTFSRealTimeProviderExt.kt
@@ -25,6 +25,7 @@ import org.mtransit.android.commons.provider.GTFSRealTimeProvider.getAgencyTagTa
 import org.mtransit.android.commons.provider.GTFSRealTimeProvider.getTARGET_AUTHORITY
 import org.mtransit.android.commons.provider.GTFSRealTimeProvider.isIGNORE_DIRECTION
 import org.mtransit.android.commons.provider.GTFSRealTimeProvider.isUSE_URL_HASH_SECRET_AND_DATE
+import org.mtransit.android.commons.provider.gtfs.GtfsRealtimeExt.optAgencyId
 import org.mtransit.android.commons.provider.gtfs.GtfsRealtimeExt.optRouteId
 import org.mtransit.android.commons.provider.gtfs.GtfsRealtimeExt.optStopId
 import org.mtransit.android.commons.provider.gtfs.GtfsRealtimeExt.optTripId
@@ -40,14 +41,18 @@ val GTFSRealTimeProvider.ignoreDirection get() = isIGNORE_DIRECTION(requireConte
 val GTFSRealTimeProvider.targetAuthority get() = getTARGET_AUTHORITY(requireContextCompat())
 val GTFSRealTimeProvider.timeZone get() = getAGENCY_TIME_ZONE(requireContextCompat())
 
-private val GTFSRealTimeProvider.routeIdCleanupPattern get() = getRouteIdCleanupPattern(requireContextCompat())
+fun GTFSRealTimeProvider.parseAgencyId(es: GEntitySelector) = es.optAgencyId?.let { parseAgencyId(it) }
+fun GTFSRealTimeProvider.parseAgencyId(gAgencyId: String) = gAgencyId.originalIdToId(agencyIdCleanupPattern)
+private val GTFSRealTimeProvider.agencyIdCleanupPattern get() = getAgencyIdCleanupPattern(requireContextCompat())
+
 fun GTFSRealTimeProvider.parseRouteId(es: GEntitySelector) = es.optRouteId?.let { parseRouteId(it) }
 fun GTFSRealTimeProvider.parseRouteId(td: GTripDescriptor) = td.optRouteId?.let { parseRouteId(it) }
 fun GTFSRealTimeProvider.parseRouteId(gRouteId: String) = gRouteId.originalIdToHash(routeIdCleanupPattern)
+private val GTFSRealTimeProvider.routeIdCleanupPattern get() = getRouteIdCleanupPattern(requireContextCompat())
 
-private val GTFSRealTimeProvider.tripIdCleanupPattern get() = getTripIdCleanupPattern(requireContextCompat())
 fun GTFSRealTimeProvider.parseTripId(td: GTripDescriptor) = td.optTripId?.let { parseTripId(it) }
 fun GTFSRealTimeProvider.parseTripId(gTripId: String) = gTripId.originalIdToId(tripIdCleanupPattern)
+private val GTFSRealTimeProvider.tripIdCleanupPattern get() = getTripIdCleanupPattern(requireContextCompat())
 
 @Suppress("unused")
 fun GTFSRealTimeProvider.parseStopId(stu: GTUStopTimeUpdate) = stu.optStopId?.let { parseStopId(it) }
diff --git a/src/main/res/values/gtfs_rts_values_gen.xml b/src/main/res/values/gtfs_rts_values_gen.xml
index a527184f..1a56bc74 100644
--- a/src/main/res/values/gtfs_rts_values_gen.xml
+++ b/src/main/res/values/gtfs_rts_values_gen.xml
@@ -8,6 +8,7 @@
     <integer name="gtfs_rts_agency_extended_type">-1</integer> <!-- -1: set in module app -->
     <string name="gtfs_rts_timezone" /> <!-- empty: set in module app -->
     <string name="gtfs_rts_color" /> <!-- empty: set in module app -->
+    <string name="gtfs_rts_agency_id_cleanup_regex" /> <!-- empty: set in module app -->
     <string name="gtfs_rts_service_id_cleanup_regex" /> <!-- empty: set in module app -->
     <string name="gtfs_rts_route_id_cleanup_regex" /> <!-- empty: set in module app -->
     <string name="gtfs_rts_trip_id_cleanup_regex" /> <!-- empty: set in module app -->