diff --git a/src/core/border_router/routing_manager.hpp b/src/core/border_router/routing_manager.hpp
index 1ababf2fe..84d6bc3c3 100644
--- a/src/core/border_router/routing_manager.hpp
+++ b/src/core/border_router/routing_manager.hpp
@@ -194,7 +194,7 @@ private:
     static constexpr uint8_t kMaxOmrPrefixNum = OPENTHREAD_CONFIG_IP6_SLAAC_NUM_ADDRESSES;
 
     // The maximum number of prefixes to discover on the infra link.
-    static constexpr uint8_t kMaxDiscoveredPrefixNum = 8;
+    static constexpr uint8_t kMaxDiscoveredPrefixNum = OPENTHREAD_CONFIG_BORDER_ROUTING_MAX_DISCOVERED_PREFIXES;
 
     static constexpr uint8_t kOmrPrefixLength    = OT_IP6_PREFIX_BITSIZE; // The length of an OMR prefix. In bits.
     static constexpr uint8_t kOnLinkPrefixLength = OT_IP6_PREFIX_BITSIZE; // The length of an On-link prefix. In bits.
diff --git a/src/core/config/border_router.h b/src/core/config/border_router.h
index 18b4d3336..5e45b387a 100644
--- a/src/core/config/border_router.h
+++ b/src/core/config/border_router.h
@@ -65,6 +65,16 @@
 #define OPENTHREAD_CONFIG_BORDER_ROUTING_ENABLE 0
 #endif
 
+/**
+ * @def OPENTHREAD_CONFIG_BORDER_ROUTING_MAX_DISCOVERED_PREFIXES
+ *
+ * Specifies maximum number of discovered prefixes (on-link prefixes on the infra link) maintained by routing manager.
+ *
+ */
+#ifndef OPENTHREAD_CONFIG_BORDER_ROUTING_MAX_DISCOVERED_PREFIXES
+#define OPENTHREAD_CONFIG_BORDER_ROUTING_MAX_DISCOVERED_PREFIXES 8
+#endif
+
 /**
  * @def OPENTHREAD_CONFIG_BORDER_ROUTING_VICARIOUS_RS_ENABLE
  *