diff --git a/routes/acars.py b/routes/acars.py
index 186970f..accce19 100644
--- a/routes/acars.py
+++ b/routes/acars.py
@@ -35,11 +35,8 @@ acars_bp = Blueprint('acars', __name__, url_prefix='/acars')
 
 # Default VHF ACARS frequencies (MHz) - common worldwide
 DEFAULT_ACARS_FREQUENCIES = [
-    '131.550',  # Primary worldwide
-    '130.025',  # Secondary USA/Canada
-    '129.125',  # USA
-    '131.525',  # Europe
-    '131.725',  # Europe secondary
+    '131.725',  # North America
+    '131.825',  # North America
 ]
 
 # Message counter for statistics
@@ -447,7 +444,7 @@ def get_frequencies() -> Response:
     return jsonify({
         'default': DEFAULT_ACARS_FREQUENCIES,
         'regions': {
-            'north_america': ['129.125', '130.025', '130.450', '131.550'],
+            'north_america': ['131.725', '131.825'],
             'europe': ['131.525', '131.725', '131.550'],
             'asia_pacific': ['131.550', '131.450'],
         }
diff --git a/routes/aprs.py b/routes/aprs.py
index 8f2ce93..bce11fe 100644
--- a/routes/aprs.py
+++ b/routes/aprs.py
@@ -47,6 +47,7 @@ APRS_FREQUENCIES = {
     'brazil': '145.570',
     'japan': '144.640',
     'china': '144.640',
+    'iss': '145.825',
 }
 
 # Statistics
diff --git a/templates/adsb_dashboard.html b/templates/adsb_dashboard.html
index 9917cf2..05553cc 100644
--- a/templates/adsb_dashboard.html
+++ b/templates/adsb_dashboard.html
@@ -3332,7 +3332,7 @@ sudo make install</code>
         let acarsMessageCount = 0;
         let acarsSidebarCollapsed = localStorage.getItem('acarsSidebarCollapsed') !== 'false';
         let acarsFrequencies = {
-            'na': ['129.125', '130.025', '130.450', '131.550'],
+            'na': ['131.725', '131.825'],
             'eu': ['131.525', '131.725', '131.550'],
             'ap': ['131.550', '131.450']
         };
diff --git a/templates/index.html b/templates/index.html
index 2f19aee..a8b977c 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -1009,6 +1009,7 @@
                                     <option value="brazil">Brazil (145.570)</option>
                                     <option value="japan">Japan (144.640)</option>
                                     <option value="china">China (144.640)</option>
+                                    <option value="iss">ISS (145.825)</option>
                                     <option value="custom">Custom Frequency</option>
                                 </select>
                             </div>
diff --git a/templates/partials/modes/acars.html b/templates/partials/modes/acars.html
index 28fb776..6627bac 100644
--- a/templates/partials/modes/acars.html
+++ b/templates/partials/modes/acars.html
@@ -56,8 +56,8 @@
                 <strong style="color: var(--accent-cyan); font-size: 12px;">Quick Reference</strong>
                 <table style="width: 100%; margin-top: 6px; font-size: 10px; border-collapse: collapse;">
                     <tr style="border-bottom: 1px solid var(--border-color);">
-                        <td style="padding: 3px 4px; color: var(--text-dim);">Primary (worldwide)</td>
-                        <td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">131.550 MHz</td>
+                        <td style="padding: 3px 4px; color: var(--text-dim);">Primary (N. America)</td>
+                        <td style="padding: 3px 4px; color: var(--text-primary); text-align: right;">131.725 / 131.825 MHz</td>
                     </tr>
                     <tr style="border-bottom: 1px solid var(--border-color);">
                         <td style="padding: 3px 4px; color: var(--text-dim);">Quarter-wave length</td>
@@ -89,7 +89,7 @@
     let acarsMainMsgCount = 0;
 
     const acarsMainFrequencies = {
-        'na': ['129.125', '130.025', '130.450', '131.550'],
+        'na': ['131.725', '131.825'],
         'eu': ['131.525', '131.725', '131.550'],
         'ap': ['131.550', '131.450']
     };