Exhibit 8.1





LIST OF CERTAIN
SUBSIDIARIES OF AMÉRICA MÓVIL, S.A.B. DE C.V.

As of March 31, 2017



|                                                                        |  |                    |  |                   |       |  |               |                                
|----------------------------------------------------------------------- |  | ------------------ |  | ----------------- | ----- |  | ------------- | -------------------------------
|Name of Company                                                         |  | Jurisdiction       |  | OwnershipInterest |       |  | Main Activity
|AMX Tenedora, S.A. de C.V.                                              |  | Mexico             |  |                   | 100.0 |  |               | Holding Company                
|Compañía Dominicana de Teléfonos, S. A.
(Codetel)                       |  | Dominican Republic |  |                   | 100.0 |  |               | Fixed-line/Wireless            
|Sercotel, S.A. de C.V.                                                  |  | Mexico             |  |                   | 100.0 |  |               | Holding Company                
|Radiomóvil Dipsa, S.A. de C.V. and subsidiaries
(Telcel)                |  | Mexico             |  |                   | 100.0 |  |               | Wireless                       
|Puerto Rico Telephone Company, Inc.                                     |  | Puerto Rico        |  |                   | 100.0 |  |               | Fixed-line/Wireless            
|Servicios de Comunicaciones de Honduras, S.A. de C.V.
(Sercom Honduras) |  | Honduras           |  |                   | 100.0 |  |               | Wireless                       
|TracFone Wireless, Inc.                                                 |  | USA                |  |                   | 100.0 |  |               | Wireless                       
|Claro Telecom Participacões, S.A.                                       |  | Brazil             |  |                   | 100.0 |  |               | Holding Company                
|Americel S.A.                                                           |  | Brazil             |  |                   | 99.9  |  |               | Wireless                       
|Telecomunicaciones de Guatemala, S.A.                                   |  | Guatemala          |  |                   | 99.3  |  |               | Fixed-line/Wireless            
|Empresa Nicaragüense de Telecomunicaciones, S.A.                        |  | Nicaragua          |  |                   | 99.6  |  |               | Fixed-line/Wireless            
|Estesa Holding Corp.                                                    |  | Panama             |  |                   | 100.0 |  |               | Holding Company                
|Cablenet, S.A.                                                          |  | Nicaragua          |  |                   | 100.0 |  |               | Cable TV                       
|Estaciones Terrenas de Satélite, S.A. (Estesa)                          |  | Nicaragua          |  |                   | 100.0 |  |               | Cable TV                       
|Compañía de Telecomunicaciones de El Salvador
(CTE), S.A. de C.V.       |  | El Salvador        |  |                   | 95.8  |  |               | Fixed-line                     
|Cablenet, S.A. (Cablenet)                                               |  | Guatemala          |  |                   | 95.8  |  |               | Fixed-line                     
|Telecomoda, S.A. de C.V. (Telecomoda)                                   |  | El Salvador        |  |                   | 95.8  |  |               | Directories Provider           
|CTE Telecom Personal, S.A. de C.V.                                      |  | El Salvador        |  |                   | 95.8  |  |               | Wireless                       
|Comunicación Celular S.A. (Comcel)                                      |  | Colombia           |  |                   | 99.4  |  |               | Wireless                       
|Telmex Colombia, S.A.                                                   |  | Colombia           |  |                   | 99.3  |  |               | Fixed-line/Cable TV            
|Consorcio Ecuatoriano de Telecomunicaciones, S.A. (Conecel)             |  | Ecuador            |  |                   | 100.0 |  |               | Wireless                       
|AMX Argentina, S.A.                                                     |  | Argentina          |  |                   | 100.0 |  |               | Wireless                       
|Telstar, S.A.                                                           |  | Uruguay            |  |                   | 99.9  |  |               | Fixed-line                     
|Flimay, S.A.                                                            |  | Uruguay            |  |                   | 99.9  |  |               | DTH                            
|Ertach, S.A.                                                            |  | Argentina          |  |                   | 99.8  |  |               | Wireless                       
|Telmex Argentina, S.A.                                                  |  | Argentina          |  |                   | 99.7  |  |               | Services to Corporate Customers
|AMX Paraguay, S.A.                                                      |  | Paraguay           |  |                   | 100.0 |  |               | Wireless                       
|AM Wireless Uruguay, S.A.                                               |  | Uruguay            |  |                   | 100.0 |  |               | Wireless                       
|Claro Chile S.A.                                                        |  | Chile              |  |                   | 100.0 |  |               | Wireless                       



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|                                                              |  |              |  |                   |       |  |               |                                               
|------------------------------------------------------------- |  | ------------ |  | ----------------- | ----- |  | ------------- | ----------------------------------------------
|Name of Company                                               |  | Jurisdiction |  | OwnershipInterest |       |  | Main Activity
|Claro Servicios Empresariales, S.A.                           |  | Chile        |  |                   | 98.2  |  |               | Fixed-line/Wireless                           
|América Móvil Perú, S.A.                                      |  | Peru         |  |                   | 100.0 |  |               | Wireless                                      
|Claro Panamá, S.A.                                            |  | Panama       |  |                   | 100.0 |  |               | Wireless                                      
|Carso Telecom B.V. (formerly known as Amov Europa B.V.)       |  | Netherlands  |  |                   | 100.0 |  |               | Holding Company                               
|Telekom Austria Aktiengesellschaft                            |  | Austria      |  |                   | 51.0  |  |               | Holding Company                               
|Teléfonos de México, S.A.B. de C.V.                           |  | Mexico       |  |                   | 98.7  |  |               | Fixed-line                                    
|Integración de Servicios TMX, S.A. de C.V.                    |  | Mexico       |  |                   | 98.7  |  |               | Holding Company                               
|Consorcio Red Uno, S.A. de C.V.                               |  | Mexico       |  |                   | 98.7  |  |               | Telecommunications NetworkIntegration Services
|Teléfonos del Noroeste, S.A. de C.V.                          |  | Mexico       |  |                   | 98.7  |  |               | Fixed-line                                    
|Uninet, S.A. de C.V.                                          |  | Mexico       |  |                   | 98.7  |  |               | Corporate networks andInternet Access Services
|Teninver, S.A. de C.V.                                        |  | Mexico       |  |                   | 98.7  |  |               | Leasing                                       
|Telmex USA, L.L.C.                                            |  | USA          |  |                   | 98.7  |  |               | Fixed-line                                    
|Empresa de Servicios y Soporte Integral GC, S.A.P.I. de C.V.  |  | Mexico       |  |                   | 98.7  |  |               | Holding Company                               
|Alquiladora de Casas, S.A. de C.V.                            |  | Mexico       |  |                   | 98.7  |  |               | Real Estate                                   
|Compañía de Teléfonos y Bienes Raíces,
S.A. de C.V.           |  | Mexico       |  |                   | 98.7  |  |               | Real Estate                                   
|Renta de Equipo, S.A. de C.V.                                 |  | Mexico       |  |                   | 98.7  |  |               | Leasing                                       
|Telmex Internacional, S.A. de C.V.                            |  | Mexico       |  |                   | 97.8  |  |               | Holding Company                               
|Controladora de Servicios de Telecomunicaciones, S.A. de
C.V. |  | Mexico       |  |                   | 98.4  |  |               | Holding Company                               
|Hitss Solutions, S.A. de C.V.                                 |  | Mexico       |  |                   | 68.5  |  |               | Information Technology                        
|Claro Comunicaciones, S.A.                                    |  | Chile        |  |                   | 98.2  |  |               | Fixed-line/Wireless                           
|Sección Amarilla USA, LLC                                     |  | USA          |  |                   | 98.4  |  |               | Directories Provider                          
|Publicidad y Contenido Editorial, S.A. de C.V.                |  | Mexico       |  |                   | 98.4  |  |               | Provider of CableTelevision Content           
|Editorial Contenido, S.A. de C.V.                             |  | Mexico       |  |                   | 98.4  |  |               | Magazine Editor                               
|Claro S.A.                                                    |  | Brazil       |  |                   | 97.7  |  |               | Fixed-line/Wireless/Cable TV                  
|Star One S.A.                                                 |  | Brazil       |  |                   | 97.7  |  |               | Satellite Services Provider