diff --git a/src/components/DXFilterManager.jsx b/src/components/DXFilterManager.jsx
index 377da25..a9c69b6 100644
--- a/src/components/DXFilterManager.jsx
+++ b/src/components/DXFilterManager.jsx
@@ -279,7 +279,7 @@ export const DXFilterManager = ({ filters, onFilterChange, isOpen, onClose }) =>
     <div>
       <div style={{ marginBottom: '16px' }}>
         <div style={{ fontSize: '13px', fontWeight: '600', color: 'var(--text-primary)', marginBottom: '8px' }}>
-          Exclude List - Hide these callsigns
+          Exclude List - Hide DX callsigns beginning with:
         </div>
         <div style={{ display: 'flex', gap: '8px' }}>
           <input
diff --git a/src/hooks/useDXCluster.js b/src/hooks/useDXCluster.js
index 571f1bb..60a574c 100644
--- a/src/hooks/useDXCluster.js
+++ b/src/hooks/useDXCluster.js
@@ -26,17 +26,15 @@ export const useDXCluster = (source = 'auto', filters = {}) => {
       // Watchlist only mode - must match watchlist
       if (filters.watchlistOnly && filters.watchlist?.length > 0) {
         const matchesWatchlist = filters.watchlist.some(w => 
-          spot.call?.toUpperCase().includes(w.toUpperCase()) ||
-          spot.spotter?.toUpperCase().includes(w.toUpperCase())
+          spot.call?.toUpperCase().includes(w.toUpperCase())
         );
         if (!matchesWatchlist) return false;
       }
       
-      // Exclude list - hide matching calls
+      // Exclude list - hide matching calls - match the call as a prefix
       if (filters.excludeList?.length > 0) {
         const isExcluded = filters.excludeList.some(exc =>
-          spot.call?.toUpperCase().includes(exc.toUpperCase()) ||
-          spot.spotter?.toUpperCase().includes(exc.toUpperCase())
+          spot.call?.toUpperCase().startsWith(exc.toUpperCase())
         );
         if (isExcluded) return false;
       }
diff --git a/src/utils/callsign.js b/src/utils/callsign.js
index 2207fa2..64b829d 100644
--- a/src/utils/callsign.js
+++ b/src/utils/callsign.js
@@ -242,8 +242,7 @@ export const filterDXPaths = (paths, filters) => {
     // Exclude list - hide matching callsigns
     if (filters.excludeList?.length > 0) {
       const isExcluded = filters.excludeList.some(e =>
-        path.dxCall?.toUpperCase().includes(e.toUpperCase()) ||
-        path.spotter?.toUpperCase().includes(e.toUpperCase())
+        path.dxCall?.toUpperCase().startsWith(e.toUpperCase())
       );
       if (isExcluded) return false;
     }