diff --git a/rust/bt-bass/src/client.rs b/rust/bt-bass/src/client.rs
index 8970b1e..d6d239f 100644
--- a/rust/bt-bass/src/client.rs
+++ b/rust/bt-bass/src/client.rs
@@ -737,7 +737,7 @@
             BroadcastId::try_from(0x11).unwrap(),
             AddressType::Public,
             [0x04, 0x10, 0x00, 0x00, 0x00, 0x00],
-            AdvertisingSetId(1),
+            AdvertisingSetId::try_from(1).unwrap(),
             PaSync::DoNotSync,
             PeriodicAdvertisingInterval::unknown(),
             vec![],
@@ -759,7 +759,7 @@
                 source_id: 0x11,
                 source_address_type: AddressType::Public,
                 source_address: [1, 2, 3, 4, 5, 6],
-                source_adv_sid: AdvertisingSetId(1),
+                source_adv_sid: AdvertisingSetId::try_from(1).unwrap(),
                 broadcast_id: BroadcastId::try_from(0x11).unwrap(),
                 pa_sync_state: PaSyncState::Synced,
                 big_encryption: EncryptionStatus::BroadcastCodeRequired,
@@ -801,7 +801,7 @@
                 source_id: 0x11,
                 source_address_type: AddressType::Public,
                 source_address: [1, 2, 3, 4, 5, 6],
-                source_adv_sid: AdvertisingSetId(1),
+                source_adv_sid: AdvertisingSetId::try_from(1).unwrap(),
                 broadcast_id: BroadcastId::try_from(0x11).unwrap(),
                 pa_sync_state: PaSyncState::Synced,
                 big_encryption: EncryptionStatus::BroadcastCodeRequired,
@@ -851,7 +851,7 @@
                 source_id: 0x11,
                 source_address_type: AddressType::Public,
                 source_address: [1, 2, 3, 4, 5, 6],
-                source_adv_sid: AdvertisingSetId(1),
+                source_adv_sid: AdvertisingSetId::try_from(1).unwrap(),
                 broadcast_id: BroadcastId::try_from(0x11).unwrap(),
                 pa_sync_state: PaSyncState::Synced,
                 big_encryption: EncryptionStatus::BroadcastCodeRequired,
@@ -922,7 +922,7 @@
                 source_id: 0x11,
                 source_address_type: AddressType::Public,
                 source_address: [1, 2, 3, 4, 5, 6],
-                source_adv_sid: AdvertisingSetId(1),
+                source_adv_sid: AdvertisingSetId::try_from(1).unwrap(),
                 broadcast_id: bid,
                 pa_sync_state: PaSyncState::Synced,
                 big_encryption: EncryptionStatus::BroadcastCodeRequired,
@@ -965,7 +965,7 @@
                 source_id: 0x01,
                 source_address_type: AddressType::Public,
                 source_address: [1, 2, 3, 4, 5, 6],
-                source_adv_sid: AdvertisingSetId(1),
+                source_adv_sid: AdvertisingSetId::try_from(1).unwrap(),
                 broadcast_id: BroadcastId::try_from(0x030201).unwrap(),
                 pa_sync_state: PaSyncState::Synced,
                 big_encryption: EncryptionStatus::BroadcastCodeRequired,
diff --git a/rust/bt-bass/src/server.rs b/rust/bt-bass/src/server.rs
index 4521795..c7bbde7 100644
--- a/rust/bt-bass/src/server.rs
+++ b/rust/bt-bass/src/server.rs
@@ -293,7 +293,7 @@
 mod tests {
     use super::*;
     use bt_bap::types::BroadcastId;
-    use bt_common::core::AddressType;
+    use bt_common::core::{AddressType, AdvertisingSetId};
     use bt_gatt::server::ReadResponder;
     use bt_gatt::test_utils::{FakeServer, FakeServerEvent, FakeTypes};
     use bt_gatt::types::GattError;
@@ -322,7 +322,7 @@
             source_id,
             AddressType::Public,
             [0x01, 0x02, 0x03, 0x04, 0x05, 0x06],
-            1,
+            AdvertisingSetId::try_from(1).unwrap(),
             BroadcastId::try_from(0x123456).unwrap(),
             PaSyncState::NotSynced,
             EncryptionStatus::NotEncrypted,
diff --git a/rust/bt-bass/src/types.rs b/rust/bt-bass/src/types.rs
index b881328..2418d9e 100644
--- a/rust/bt-bass/src/types.rs
+++ b/rust/bt-bass/src/types.rs
@@ -210,7 +210,7 @@
             let advertiser_address_type = AddressType::try_from(buf[1])?;
             let mut advertiser_address = [0; ADDRESS_BYTE_SIZE];
             advertiser_address.clone_from_slice(&buf[2..8]);
-            let advertising_sid = AdvertisingSetId(buf[8]);
+            let advertising_sid = AdvertisingSetId::try_from(buf[8])?;
             let broadcast_id = BroadcastId::decode(&buf[9..12]).0?;
             let pa_sync = PaSync::try_from(buf[12])?;
             let pa_interval =
@@ -259,7 +259,7 @@
         buf[0] = Self::opcode() as u8;
         buf[1] = self.advertiser_address_type as u8;
         buf[2..8].copy_from_slice(&self.advertiser_address);
-        buf[8] = self.advertising_sid.0;
+        buf[8] = self.advertising_sid.value();
         self.broadcast_id.encode(&mut buf[9..12])?;
         buf[12] = u8::from(self.pa_sync);
         buf[13..15].copy_from_slice(&self.pa_interval.0.to_le_bytes());
@@ -767,7 +767,7 @@
         source_id: u8,
         source_address_type: AddressType,
         source_address: [u8; ADDRESS_BYTE_SIZE],
-        source_adv_sid: u8,
+        source_adv_sid: AdvertisingSetId,
         broadcast_id: BroadcastId,
         pa_sync_state: PaSyncState,
         big_encryption: EncryptionStatus,
@@ -777,7 +777,7 @@
             source_id,
             source_address_type,
             source_address,
-            source_adv_sid: AdvertisingSetId(source_adv_sid),
+            source_adv_sid,
             broadcast_id,
             pa_sync_state,
             big_encryption,
@@ -815,7 +815,7 @@
             let source_address_type = AddressType::try_from(buf[1])?;
             let mut source_address = [0; ADDRESS_BYTE_SIZE];
             source_address.clone_from_slice(&buf[2..8]);
-            let source_adv_sid = AdvertisingSetId(buf[8]);
+            let source_adv_sid = AdvertisingSetId::try_from(buf[8])?;
             let broadcast_id = BroadcastId::decode(&buf[9..12]).0?;
             let pa_sync_state = PaSyncState::try_from(buf[12])?;
 
@@ -876,7 +876,7 @@
         buf[0] = self.source_id;
         buf[1] = self.source_address_type as u8;
         buf[2..8].copy_from_slice(&self.source_address);
-        buf[8] = self.source_adv_sid.0;
+        buf[8] = self.source_adv_sid.value();
         self.broadcast_id.encode(&mut buf[9..12])?;
         buf[12] = u8::from(self.pa_sync_state);
         let mut idx = 13 + self.big_encryption.encoded_len();
@@ -1177,7 +1177,7 @@
         let op = AddSourceOperation::new(
             AddressType::Public,
             [0x04, 0x10, 0x00, 0x00, 0x00, 0x00],
-            AdvertisingSetId(1),
+            AdvertisingSetId::try_from(1).unwrap(),
             BroadcastId::try_from(0x11).unwrap(),
             PaSync::DoNotSync,
             PeriodicAdvertisingInterval::unknown(),
@@ -1209,7 +1209,7 @@
         let op = AddSourceOperation::new(
             AddressType::Random,
             [0x04, 0x10, 0x00, 0x00, 0x00, 0x00],
-            AdvertisingSetId(1),
+            AdvertisingSetId::try_from(1).unwrap(),
             BroadcastId::try_from(0x11).unwrap(),
             PaSync::SyncPastAvailable,
             PeriodicAdvertisingInterval::unknown(),
@@ -1234,6 +1234,25 @@
     }
 
     #[test]
+    fn invalid_advertising_sid_decoding() {
+        // AddSourceOperation with invalid Advertising_SID (0x10 > 0x0F)
+        let invalid_add_source_bytes = vec![
+            0x02, 0x00, 0x04, 0x10, 0x00, 0x00, 0x00, 0x00, 0x10, 0x11, 0x00, 0x00, 0x00, 0xFF,
+            0xFF, 0x00,
+        ];
+        let (decoded, _) = AddSourceOperation::decode(&invalid_add_source_bytes);
+        assert_eq!(decoded, Err(PacketError::OutOfRange));
+
+        // ReceiveState with invalid Advertising_SID (0x10 > 0x0F)
+        let invalid_receive_state_bytes = vec![
+            0x01, 0x00, 0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x10, 0x03, 0x02, 0x01, 0x02, 0x00,
+            0x00,
+        ];
+        let (decoded, _) = BroadcastReceiveState::decode(&invalid_receive_state_bytes);
+        assert_eq!(decoded, Err(PacketError::OutOfRange));
+    }
+
+    #[test]
     fn modify_source_without_subgroups() {
         // Encoding operation with no subgroups.
         let op = ModifySourceOperation::new(
@@ -1336,7 +1355,7 @@
             source_id: 0x01,
             source_address_type: AddressType::Public,
             source_address: [0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A],
-            source_adv_sid: AdvertisingSetId(0x01),
+            source_adv_sid: AdvertisingSetId::try_from(0x01).unwrap(),
             broadcast_id: BroadcastId::try_from(0x00010203).unwrap(),
             pa_sync_state: PaSyncState::Synced,
             big_encryption: EncryptionStatus::BadCode([
@@ -1370,7 +1389,7 @@
             source_id: 0x01,
             source_address_type: AddressType::Random,
             source_address: [0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A],
-            source_adv_sid: AdvertisingSetId(0x01),
+            source_adv_sid: AdvertisingSetId::try_from(0x01).unwrap(),
             broadcast_id: BroadcastId::try_from(0x00010203).unwrap(),
             pa_sync_state: PaSyncState::NotSynced,
             big_encryption: EncryptionStatus::NotEncrypted,
diff --git a/rust/bt-broadcast-assistant/src/assistant.rs b/rust/bt-broadcast-assistant/src/assistant.rs
index b41dcd1..fe6e6a2 100644
--- a/rust/bt-broadcast-assistant/src/assistant.rs
+++ b/rust/bt-broadcast-assistant/src/assistant.rs
@@ -291,7 +291,7 @@
     fn merge_broadcast_source() {
         let discovered = DiscoveredBroadcastSources::new();
         let bid1 = BroadcastId::try_from(1001).unwrap();
-        let key1 = (PeerId(1001), AdvertisingSetId(1));
+        let key1 = (PeerId(1001), AdvertisingSetId::try_from(1).unwrap());
 
         // 1. Merge initial source data for SID 1.
         let (bs, changed) = discovered.merge_broadcast_source_data(
@@ -353,7 +353,7 @@
         // 4. Merge a new broadcast source with a different SID (SID 2) for the same
         //    peer.
         let bid2 = BroadcastId::try_from(1002).unwrap();
-        let key2 = (PeerId(1001), AdvertisingSetId(2));
+        let key2 = (PeerId(1001), AdvertisingSetId::try_from(2).unwrap());
         let (bs, changed) = discovered.merge_broadcast_source_data(
             &key2,
             &BroadcastSource::default()
@@ -381,9 +381,9 @@
         // Verify get_by_broadcast_id works for both and maps to correct keys
         let lock = discovered.0.lock();
         let entry1 = lock.iter().find(|(_, v)| v.broadcast_id == Some(bid1)).unwrap();
-        assert_eq!(entry1.0 .1, AdvertisingSetId(1));
+        assert_eq!(entry1.0 .1, AdvertisingSetId::try_from(1).unwrap());
         let entry2 = lock.iter().find(|(_, v)| v.broadcast_id == Some(bid2)).unwrap();
-        assert_eq!(entry2.0 .1, AdvertisingSetId(2));
+        assert_eq!(entry2.0 .1, AdvertisingSetId::try_from(2).unwrap());
     }
 
     #[test]
@@ -427,7 +427,7 @@
         let peer_id = PeerId(1);
         let address = [1, 2, 3, 4, 5, 6];
         let address_type = AddressType::Public;
-        let sid = AdvertisingSetId(1);
+        let sid = AdvertisingSetId::try_from(1).unwrap();
 
         let source =
             assistant.force_discover_broadcast_source(peer_id, address, address_type, sid).unwrap();
@@ -445,7 +445,7 @@
         let assistant = BroadcastAssistant::<FakeTypes>::new(FakeCentral::new());
         let peer_id = PeerId(1);
         let metadata = vec![vec![Metadata::BroadcastAudioImmediateRenderingFlag]];
-        let sid = AdvertisingSetId(1);
+        let sid = AdvertisingSetId::try_from(1).unwrap();
 
         let source = assistant
             .force_discover_broadcast_source_metadata(peer_id, sid, metadata.clone())
diff --git a/rust/bt-broadcast-assistant/src/assistant/event.rs b/rust/bt-broadcast-assistant/src/assistant/event.rs
index 1780cf1..656ff93 100644
--- a/rust/bt-broadcast-assistant/src/assistant/event.rs
+++ b/rust/bt-broadcast-assistant/src/assistant/event.rs
@@ -203,18 +203,24 @@
             return None;
         };
 
+        let Ok(advertising_sid) = AdvertisingSetId::try_from(sid) else {
+            return None;
+        };
+
         let (broadcast_source, changed) = self.broadcast_sources.merge_broadcast_source_data(
-            &(peer_id, AdvertisingSetId(sid)),
+            &(peer_id, advertising_sid),
             &BroadcastSource::default().with_endpoint(base),
         );
 
         if broadcast_source.is_ready_to_add() && changed {
-            if let Some(Some(handle)) = self.active_syncs.remove(&(peer_id, sid)) {
+            if let Some(Some(handle)) =
+                self.active_syncs.remove(&(peer_id, advertising_sid.value()))
+            {
                 handle.abort();
             }
             return Some(Event::FoundBroadcastSource {
                 peer: peer_id,
-                advertising_sid: AdvertisingSetId(sid),
+                advertising_sid,
                 source: broadcast_source,
             });
         }
@@ -233,7 +239,9 @@
         let Some(raw_sid) = scanned.advertising_sid else {
             return None;
         };
-        let sid = AdvertisingSetId(raw_sid);
+        let Ok(sid) = AdvertisingSetId::try_from(raw_sid) else {
+            return None;
+        };
 
         let (broadcast_source, changed) =
             self.broadcast_sources.merge_broadcast_source_data(&(scanned.id, sid), &found_source);
@@ -261,7 +269,7 @@
 
         // If we are already actively syncing (or establishing a sync) for this
         // peer/SID, don't start another one.
-        let key = (scanned.id, sid.0);
+        let key = (scanned.id, sid.value());
         if self.active_syncs.contains_key(&key) {
             return None;
         }
@@ -269,10 +277,10 @@
         self.active_syncs.insert(key, None);
         let fut = pa.sync_to_advertising_reports(
             scanned.id,
-            sid.0,
+            sid.value(),
             SyncConfiguration { filter_duplicates: true },
         );
-        let mapped_fut = fut.map(move |res| (scanned.id, sid.0, res));
+        let mapped_fut = fut.map(move |res| (scanned.id, sid.value(), res));
         self.establishing_periodic_advertising_syncs.push(Box::pin(mapped_fut));
 
         None
@@ -431,7 +439,7 @@
 
         // Pretend somehow address, address type were filled out.
         let _ = stream.broadcast_sources.merge_broadcast_source_data(
-            &(broadcast_source_pid, AdvertisingSetId(1)),
+            &(broadcast_source_pid, AdvertisingSetId::try_from(1).unwrap()),
             &BroadcastSource::default()
                 .with_address([1, 2, 3, 4, 5, 6])
                 .with_address_type(AddressType::Public),
@@ -480,7 +488,7 @@
         };
         assert_matches!(event, Event::FoundBroadcastSource { peer, advertising_sid, source } => {
             assert_eq!(peer, broadcast_source_pid);
-            assert_eq!(advertising_sid, AdvertisingSetId(1));
+            assert_eq!(advertising_sid, AdvertisingSetId::try_from(1).unwrap());
             assert_eq!(source.periodic_advertising_interval, Some(PeriodicAdvertisingInterval(0x0100)));
             assert_eq!(source.address, Some([1, 2, 3, 4, 5, 6]));
             assert_eq!(source.broadcast_name, Some("Test Broadcast".to_string()));
diff --git a/rust/bt-broadcast-assistant/src/assistant/peer.rs b/rust/bt-broadcast-assistant/src/assistant/peer.rs
index 4c8e6e4..2527fb6 100644
--- a/rust/bt-broadcast-assistant/src/assistant/peer.rs
+++ b/rust/bt-broadcast-assistant/src/assistant/peer.rs
@@ -287,7 +287,7 @@
         {
             let fut = peer.add_broadcast_source(
                 PeerId(1001),
-                AdvertisingSetId(1),
+                AdvertisingSetId::try_from(1).unwrap(),
                 &FakeGetPeerAddr,
                 PaSync::SyncPastUnavailable,
                 HashMap::new(),
@@ -298,7 +298,7 @@
         }
 
         let _ = broadcast_source.merge_broadcast_source_data(
-            &(PeerId(1001), AdvertisingSetId(1)),
+            &(PeerId(1001), AdvertisingSetId::try_from(1).unwrap()),
             &BroadcastSource::default().with_broadcast_id(BroadcastId::try_from(1001).unwrap()),
         );
 
@@ -308,7 +308,7 @@
                 StaticPeerAddr::new_for_peer(PeerId(1002), [1, 2, 3, 4, 5, 6], AddressType::Public);
             let fut = peer.add_broadcast_source(
                 PeerId(1001),
-                AdvertisingSetId(1),
+                AdvertisingSetId::try_from(1).unwrap(),
                 &address_lookup,
                 PaSync::SyncPastUnavailable,
                 HashMap::new(),
@@ -324,7 +324,7 @@
                 StaticPeerAddr::new_for_peer(PeerId(1001), [1, 2, 3, 4, 5, 6], AddressType::Public);
             let fut = peer.add_broadcast_source(
                 PeerId(1001),
-                AdvertisingSetId(1),
+                AdvertisingSetId::try_from(1).unwrap(),
                 &address_lookup,
                 PaSync::SyncPastUnavailable,
                 HashMap::new(),
diff --git a/rust/bt-broadcast-assistant/src/debug.rs b/rust/bt-broadcast-assistant/src/debug.rs
index abd545f..b369c4e 100644
--- a/rust/bt-broadcast-assistant/src/debug.rs
+++ b/rust/bt-broadcast-assistant/src/debug.rs
@@ -151,6 +151,11 @@
     raw_id.try_into().map_err(|e| format!("{e:?}"))
 }
 
+fn parse_advertising_sid(input: &str) -> Result<AdvertisingSetId, String> {
+    let raw_sid: u8 = parse_int(input).map_err(|_| format!("failed to parse int from {input}"))?;
+    AdvertisingSetId::try_from(raw_sid).map_err(|e| format!("{e:?}"))
+}
+
 fn parse_bis_sync(input: &str) -> HashMap<SubgroupIndex, BisSync> {
     let mut map = HashMap::new();
     for t in input.split(',') {
@@ -297,11 +302,10 @@
                         return Ok(());
                     };
 
-                    let Ok(sid_val) = parse_int::<u8>(&args[1]) else {
+                    let Ok(advertising_sid) = parse_advertising_sid(&args[1]) else {
                         eprintln!("invalid advertising sid: {}", args[1]);
                         return Ok(());
                     };
-                    let advertising_sid = AdvertisingSetId(sid_val);
 
                     let pa_sync: PaSync = match args[2].parse() {
                         Ok(sync) => sync,
@@ -407,11 +411,10 @@
                         }
                     };
 
-                    let Ok(raw_ad_sid) = parse_int::<u8>(&args[3]) else {
+                    let Ok(advertising_sid) = parse_advertising_sid(&args[3]) else {
                         eprintln!("invalid advertising sid: {}", args[3]);
                         return Ok(());
                     };
-                    let advertising_sid = AdvertisingSetId(raw_ad_sid);
 
                     match self.assistant.force_discover_broadcast_source(
                         source_peer_id,
@@ -442,11 +445,10 @@
                         return Ok(());
                     };
 
-                    let Ok(raw_ad_sid) = parse_int::<u8>(&args[1]) else {
+                    let Ok(advertising_sid) = parse_advertising_sid(&args[1]) else {
                         eprintln!("invalid advertising sid: {}", args[1]);
                         return Ok(());
                     };
-                    let advertising_sid = AdvertisingSetId(raw_ad_sid);
 
                     let mut all_big_metadata = Vec::new();
                     for i in 2..args.len() {
@@ -495,11 +497,10 @@
                         return Ok(());
                     };
 
-                    let Ok(raw_ad_sid) = parse_int::<u8>(&args[1]) else {
+                    let Ok(advertising_sid) = parse_advertising_sid(&args[1]) else {
                         eprintln!("invalid advertising sid: {}", args[1]);
                         return Ok(());
                     };
-                    let advertising_sid = AdvertisingSetId(raw_ad_sid);
 
                     let Ok(num_big) = parse_int::<usize>(&args[2]) else {
                         eprintln!("invalid # of bigs: {}", args[2]);
diff --git a/rust/bt-common/src/core.rs b/rust/bt-common/src/core.rs
index d9050d5..8076264 100644
--- a/rust/bt-common/src/core.rs
+++ b/rust/bt-common/src/core.rs
@@ -49,13 +49,40 @@
     }
 }
 
-/// Advertising Set ID which is 1 byte long.
+/// Advertising Set ID (SID) which is 4 bits long (range 0x00 to 0x0F).
+/// See Bluetooth Core Specification Vol 6, Part B, Section 2.3.4 and BASS
+/// v1.0.1 Section 3.1.1.4 Table 3.5.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct AdvertisingSetId(pub u8);
+pub struct AdvertisingSetId(u8);
 
 impl AdvertisingSetId {
     // Byte size if this is to be encoded.
     pub const BYTE_SIZE: usize = 1;
+
+    /// Maximum valid ID. See BASS v1.0.1 Section 3.1.1.4 Table 3.5.
+    pub const MAX_VALUE: u8 = 0x0F;
+
+    pub fn value(&self) -> u8 {
+        self.0
+    }
+}
+
+impl TryFrom<u8> for AdvertisingSetId {
+    type Error = PacketError;
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
+        if value > Self::MAX_VALUE {
+            Err(PacketError::OutOfRange)
+        } else {
+            Ok(Self(value))
+        }
+    }
+}
+
+impl From<AdvertisingSetId> for u8 {
+    fn from(sid: AdvertisingSetId) -> u8 {
+        sid.0
+    }
 }
 
 /// SyncInfo Interval value which is 2 bytes long.
@@ -292,4 +319,16 @@
             })
         );
     }
+
+    #[test]
+    fn advertising_set_id_success() {
+        assert_eq!(AdvertisingSetId::try_from(0x00).unwrap().value(), 0x00);
+        assert_eq!(AdvertisingSetId::try_from(0x0F).unwrap().value(), 0x0F);
+    }
+
+    #[test]
+    fn advertising_set_id_out_of_range() {
+        assert_eq!(AdvertisingSetId::try_from(0x10), Err(PacketError::OutOfRange));
+        assert_eq!(AdvertisingSetId::try_from(0xFF), Err(PacketError::OutOfRange));
+    }
 }