| 5 | The Tuck Shop | Retailers - other | Merthyr Tydfil | - |
| 3 | The Vulcan Inn | Pub/bar/nightclub | Merthyr Tydfil | CF47 8UD |
| 4 | The Welsh Bar | Pub/bar/nightclub | Merthyr Tydfil | CF47 8DP |
| 4 | The Welsh Cake Stall | Manufacturers/packers | Merthyr Tydfil | CF47 8EG |
| 5 | The White Horse | Pub/bar/nightclub | Merthyr Tydfil | CF47 0DN |
| 5 | The Winchester | Pub/bar/nightclub | Merthyr Tydfil | CF47 8BG |
| 5 | Thomas Jam's & Chutneys | Retailers - other | Merthyr Tydfil | CF48 1JG |
| 4 | Tien Tien Chinese Takeaway | Takeaway/sandwich shop | Merthyr Tydfil | CF46 5HE |
| 5 | Tiffin's Cafe | Restaurant/Cafe/Canteen | Merthyr Tydfil | CF48 2SR |
| 4 | Tiger Inn | Restaurant/Cafe/Canteen | Merthyr Tydfil | CF47 8UH |
| 1 | Tin Sang | Takeaway/sandwich shop | Merthyr Tydfil | CF46 5AN |
| 4 | Toomeys Munchbox | Mobile caterer | Merthyr Tydfil | CF48 2SF |
| 4 | Top Notch Indian Takeaway | Takeaway/sandwich shop | Merthyr Tydfil | CF47 0AY |
| 3 | Top Square Convenience Store | Retailers - other | Merthyr Tydfil | CF46 5HE |
| 4 | Trago Mills | Restaurant/Cafe/Canteen | Merthyr Tydfil | - |
| Exempt | Travel Lodge | Hotel/bed & breakfast/guest house | Merthyr Tydfil | CF48 1UT |
| Exempt | Treharris Community Centre | Retailers - other | Merthyr Tydfil | CF46 5ER |
| 5 | Treharris Filling Station | Retailers - other | Merthyr Tydfil | CF46 5LS |
| 5 | Treharris Phoenix RFC | Restaurant/Cafe/Canteen | Merthyr Tydfil | CF46 5HG |
| 5 | Trelewis Playgroup | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | - |
| 5 | Trelewis Primary School | School/college/university | Merthyr Tydfil | CF46 6AH |
| 5 | Trelewis minimarket | Retailers - other | Merthyr Tydfil | CF46 6AB |
| 5 | Trinity Child & Family Centre | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF48 4NT |
| 5 | Troedyrhiw Bowls Club | Restaurant/Cafe/Canteen | Merthyr Tydfil | CF48 4JQ |
| 4 | Troedyrhiw Boys & Girls Club | Other catering premises | Merthyr Tydfil | CF48 4DX |
| 5 | Troedyrhiw Ex Servicemen's Club | Pub/bar/nightclub | Merthyr Tydfil | CF48 4JU |
| 5 | Troedyrhiw Infants School | School/college/university | Merthyr Tydfil | CF48 4JJ |
| 5 | Troedyrhiw Junior School | School/college/university | Merthyr Tydfil | CF48 4JQ |
| 3 | Troz Takeaway | Takeaway/sandwich shop | Merthyr Tydfil | CF46 5NN |
| 5 | Truly Scrummy | Other catering premises | Merthyr Tydfil | CF46 |
| 3 | Twyn Fish Bar | Takeaway/sandwich shop | Merthyr Tydfil | CF47 0PP |
| 4 | Twyn Stores Premier | Retailers - other | Merthyr Tydfil | CF47 0LL |
| 5 | Twynyrodyn Community School | School/college/university | Merthyr Tydfil | CF47 0LW |
| 4 | Ty Banwen | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF46 |
| 5 | Ty Bargoed Newydd | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF46 5HH |
| 5 | Ty Cwm Day Centre | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | - |
| 5 | Ty Cwm Extra Care | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF47 0JL |
| 4 | Ty Daffodil | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF47 0HE |
| 4 | Ty Dysgu | School/college/university | Merthyr Tydfil | CF47 9SF |
| 5 | Ty Dysgu PRU | School/college/university | Merthyr Tydfil | CF48 3HW |
| 5 | Ty Gurnos Newydd | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF47 9PT |
| 4 | Ty Gwyn Newydd | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF47 8BH |
| 4 | Ty Lavendar | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF47 0HE |
| 3 | Ty Llwynog - Daisy House | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF46 |
| 3 | Ty Morgan (Rise Care Ltd) | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF46 5RH |
| Awaiting | Ty Thai | Restaurant/Cafe/Canteen | Merthyr Tydfil | CF47 8BZ |
| 5 | Usw Services Ltd (main Canteen) | Restaurant/Cafe/Canteen | Merthyr Tydfil | CF48 1AR |
| 4 | VNU | Pub/bar/nightclub | Merthyr Tydfil | CF47 8AU |
| 5 | Valley Heights | Retailers - other | Merthyr Tydfil | CF48 2YE |
| 4 | Values In Care | Hospitals/Childcare/Caring Premises | Merthyr Tydfil | CF46 5BL |