Exhibit 8.1

List of Certain Subsidiaries of América Móvil, S.A.B. de C.V.

As of
March 31, 2013



|                                                                        |  |                    |  |                      |       |  |               |                                                
|----------------------------------------------------------------------- |  | ------------------ |  | -------------------- | ----- |  | ------------- | -----------------------------------------------
|Name of Company                                                         |  | Jurisdiction       |  | OwnershipInterest(1) |       |  | 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                                
|Radiomovil 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                |  |                      | 98.2  |  |               | Wireless                                       
|Claro Telecom Participacões, S.A.                                       |  | Brazil             |  |                      | 100.0 |  |               | Holding                                        
|Claro S.A.                                                              |  | Brazil             |  |                      | 100.0 |  |               | Wireless                                       
|Americel S.A.                                                           |  | Brazil             |  |                      | 100.0 |  |               | Wireless                                       
|Telecomunicaciones de Guatemala, S.A.                                   |  | Guatemala          |  |                      | 99.3  |  |               | Fixed-line/Wireless                            
|Empresa Nicaragüense de Telecomunicaciones, S.A. (Enitel)               |  | Nicaragua          |  |                      | 99.6  |  |               | Fixed-line/Wireless                            
|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                                       
|Megacanales, S.A.S.                                                     |  | Colombia           |  |                      | 99.4  |  |               | Cable TV                                       
|The Now Operation, S.A.S.                                               |  | Colombia           |  |                      | 99.4  |  |               | Services to Cable TV Provider                  
|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                                       
|Telmex Argentina, S.A.                                                  |  | Argentina          |  |                      | 99.6  |  |               | Services to Corporate Customers                
|Telstar, S.A.                                                           |  | Uruguay            |  |                      | 99.9  |  |               | Fixed-line                                     
|Flimay, S.A.                                                            |  | Uruguay            |  |                      | 99.9  |  |               | DTH                                            
|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                                       
|Claro Servicios Empresariales, S.A.                                     |  | Chile              |  |                      | 99.3  |  |               | Fixed-line/Wireless                            
|América Móvil Perú, S.A.                                                |  | Peru               |  |                      | 100.0 |  |               | Wireless                                       
|Claro Panamá, S.A.                                                      |  | Panama             |  |                      | 100.0 |  |               | Wireless                                       
|AMOV Europa B.V.                                                        |  | Netherlands        |  |                      | 100.0 |  |               | Holding Company                                
|Carso Global Telecom, S.A. de C.V.                                      |  | Mexico             |  |                      | 99.9  |  |               | Holding Company                                
|Empresas y Controles en Comunicaciones, S.A. de C.V.                    |  | Mexico             |  |                      | 99.9  |  |               | Holding Company                                
|Teléfonos de México, S.A.B. de C.V.                                     |  | Mexico             |  |                      | 97.6  |  |               | Fixed-line                                     
|Integración de Servicios TMX, S.A. de C.V.                              |  | Mexico             |  |                      | 97.6  |  |               | Holding Company                                
|Alquiladora de Casas, S.A. de C.V.                                      |  | Mexico             |  |                      | 97.6  |  |               | Real Estate                                    
|Compañía de Teléfonos y Bienes Raíces, S.A. de C.V.                     |  | Mexico             |  |                      | 97.6  |  |               | Real Estate                                    
|Consorcio Red Uno, S.A. de C.V.                                         |  | Mexico             |  |                      | 97.6  |  |               | Telecommunications Network Integration Services
|Teléfonos del Noroeste, S.A. de C.V.                                    |  | Mexico             |  |                      | 97.6  |  |               | Fixed-line                                     
|Uninet, S.A. de C.V.                                                    |  | Mexico             |  |                      | 97.6  |  |               | Corporate networks and internet Access Services
|Telmex USA, L.L.C.                                                      |  | USA                |  |                      | 97.6  |  |               | Fixed-line                                     



---

|                                                              |  |              |  |                      |      |  |               |                                     
|------------------------------------------------------------- |  | ------------ |  | -------------------- | ---- |  | ------------- | ------------------------------------
|Name of Company                                               |  | Jurisdiction |  | OwnershipInterest(1) |      |  | Main Activity
|Telmex Internacional, S.A. de C.V.                            |  | Mexico       |  |                      | 97.6 |  |               | Holding Company                     
|Controladora de Servicios de Telecomunicaciones, S.A. de C.V. |  | México       |  |                      | 97.6 |  |               | Holding Company                     
|Ecuador Telecom, S.A.                                         |  | Ecuador      |  |                      | 97.6 |  |               | Fixed-line                          
|Empresa Brasileira de Telecomunicacões, S.A. (Embratel)       |  | Brazil       |  |                      | 95.4 |  |               | Fixed-line                          
|Star One, S.A.                                                |  | Brazil       |  |                      | 95.4 |  |               | Provider of Satellite Services      
|Net Serviços de Comunicação, S.A.                             |  | Brazil       |  |                      | 88.0 |  |               | Cable TV                            
|Ertach, S.A.                                                  |  | Argentina    |  |                      | 99.5 |  |               | Wireless                            
|Claro Comunicaciones, S.A.                                    |  | Chile        |  |                      | 97.4 |  |               | Fixed-line/ Wireless                
|Páginas Telmex Colombia, S.A.                                 |  | Colombia     |  |                      | 97.6 |  |               | Directories Provider                
|Sección Amarilla USA, LLC                                     |  | USA          |  |                      | 97.6 |  |               | Directories Provider                
|Publicidad y Contenido Editorial, S.A. de C.V.                |  | Mexico       |  |                      | 97.6 |  |               | Provider of Cable Television Content
|Editorial Contenido, S.A. de C.V.                             |  | Mexico       |  |                      | 97.6 |  |               | Magazine Editor                     



|(1) | Percentage of equity owned by América Móvil, S.A.B. de C.V. directly or indirectly through its subsidiaries and/ or affiliates.
|--- | -------------------------------------------------------------------------------------------------------------------------------