diff --git a/pySim/ts_31_102.py b/pySim/ts_31_102.py
index e68866c4..4d1c3dcb 100644
--- a/pySim/ts_31_102.py
+++ b/pySim/ts_31_102.py
@@ -1152,12 +1152,12 @@ class ADF_USIM(CardADF):
             EF_ECC(),
             EF_CBMIR(service=16),
             EF_PSLOCI(),
-            EF_ADN('6f3b', None, 'EF.FDN', 'Fixed Dialling Numbers', service=[2, 89]),
+            EF_ADN('6f3b', None, 'EF.FDN', 'Fixed Dialling Numbers', service=[2, 89], ext=2),
             EF_SMS('6f3c', None, service=10),
             EF_MSISDN(service=21),
             EF_SMSP(service=12),
             EF_SMSS(service=10),
-            EF_ADN('6f49', None, 'EF.SDN', 'Service Dialling Numbers', service=[4, 89]),
+            EF_ADN('6f49', None, 'EF.SDN', 'Service Dialling Numbers', service=[4, 89], ext=3),
             EF_EXT('6f4b', None, 'EF.EXT2', 'Extension2 (FDN)', service=3),
             EF_EXT('6f4c', None, 'EF.EXT3', 'Extension2 (SDN)', service=5),
             EF_SMSR(service=11),
@@ -1170,7 +1170,7 @@ class ADF_USIM(CardADF):
             EF_eMLPP(service=24),
             EF_AAeM(service=25),
             # EF_Hiddenkey
-            EF_ADN('6f4d', None, 'EF.BDN', 'Barred Dialling Numbers', service=6),
+            EF_ADN('6f4d', None, 'EF.BDN', 'Barred Dialling Numbers', service=6, ext=4),
             EF_EXT('6f55', None, 'EF.EXT4', 'Extension4 (BDN/SSC)', service=7),
             EF_CMI(service=6),
             EF_EST(service=[2, 6, 34, 35]),
@@ -1186,11 +1186,11 @@ class ADF_USIM(CardADF):
             TransparentEF('6fc4', None, 'EF.NETPAR', 'Network Parameters'),
             EF_PNN('6fc5', 0x19, service=45),
             EF_OPL(service=46),
-            EF_ADN('6fc7', None, 'EF.MBDN', 'Mailbox Dialling Numbers', service=47),
+            EF_ADN('6fc7', None, 'EF.MBDN', 'Mailbox Dialling Numbers', service=47, ext=6),
             EF_EXT('6fc8', None, 'EF.EXT6', 'Extension6 (MBDN)'),
             EF_MBI(service=47),
             EF_MWIS(service=48),
-            EF_ADN('6fcb', None, 'EF.CFIS', 'Call Forwarding Indication Status', service=49),
+            EF_ADN('6fcb', None, 'EF.CFIS', 'Call Forwarding Indication Status', service=49, ext=7),
             EF_EXT('6fcc', None, 'EF.EXT7', 'Extension7 (CFIS)'),
             TransparentEF('6fcd', None, 'EF.SPDI', 'Service Provider Display Information', service=51),
             EF_MMSN(service=52),
diff --git a/pySim/ts_51_011.py b/pySim/ts_51_011.py
index df1bfedb..8196a55f 100644
--- a/pySim/ts_51_011.py
+++ b/pySim/ts_51_011.py
@@ -358,14 +358,15 @@ class ExtendedBcdAdapter(Adapter):
 
 # TS 51.011 Section 10.5.1
 class EF_ADN(LinFixedEF):
-    def __init__(self, fid='6f3a', sfid=None, name='EF.ADN', desc='Abbreviated Dialing Numbers', **kwargs):
+    def __init__(self, fid='6f3a', sfid=None, name='EF.ADN', desc='Abbreviated Dialing Numbers', ext=1, **kwargs):
         super().__init__(fid, sfid=sfid, name=name, desc=desc, rec_len=(14, 30), **kwargs)
+        ext_name = 'ext%u_record_id' % ext
         self._construct = Struct('alpha_id'/COptional(GsmStringAdapter(Rpad(Bytes(this._.total_len-14)), codec='ascii')),
                                  'len_of_bcd'/Int8ub,
                                  'ton_npi'/TonNpi,
                                  'dialing_nr'/ExtendedBcdAdapter(BcdAdapter(Rpad(Bytes(10)))),
                                  'cap_conf_id'/Int8ub,
-                                 'ext1_record_id'/Int8ub)
+                                 ext_name/Int8ub)
 
 # TS 51.011 Section 10.5.5
 class EF_SMS(LinFixedEF):
@@ -497,7 +498,7 @@ class DF_TELECOM(CardDF):
         super().__init__(fid=fid, name=name, desc=desc, **kwargs)
         files = [
             EF_ADN(),
-            EF_ADN(fid='6f3b', name='EF.FDN', desc='Fixed dialling numbers'),
+            EF_ADN(fid='6f3b', name='EF.FDN', desc='Fixed dialling numbers', ext=2),
             EF_SMS(),
             LinFixedEF(fid='6f3d', name='EF.CCP',
                        desc='Capability Configuration Parameters', rec_len=(14, 14)),
@@ -507,7 +508,7 @@ class DF_TELECOM(CardDF):
             EF_SMSP(),
             EF_SMSS(),
             # LND
-            EF_ADN('6f49', None, 'EF.SDN', 'Service Dialling Numbers'),
+            EF_ADN('6f49', None, 'EF.SDN', 'Service Dialling Numbers', ext=3),
             EF_EXT('6f4a', None, 'EF.EXT1', 'Extension1 (ADN/SSC)'),
             EF_EXT('6f4b', None, 'EF.EXT2', 'Extension2 (FDN/SSC)'),
             EF_EXT('6f4c', None, 'EF.EXT3', 'Extension3 (SDN)'),