| PTS0001 | Thistle Laboratory Services (Pty) Ltd | Kyalami | Gauteng | Proficiency Testing by Interlaboratory Comparisons - Development and Operation of Proficiency Testing Schemes |
| PTS00017 | Smartspot Quality (Pty) Ltd | Parktown | Gauteng | Proficiency Testing by Interlaboratory Comporarisons |
| PTS0003 | SABS Commercial (Pty) Ltd, Food and water Chemistry - watercheck PTS | Pretoria | Gauteng | Proficiency Testing By Interlaboratory Comparisons - Water Chemical Analysis |
| PTS0005 | National Health Laboratory Service | Sandringham | Gauteng | Proficiency Testing by Interlaboratory Comparisons - Medical |
| PTS0006 | South African Blood Service (NPC) | Weltevreden Park | Gauteng | Proficiency Testing by Interlaboratory Comparisons - Medical |
| PTS0008 | Coal Concepts | Richards Bay | KwaZulu-Natal | Proficiency Testing by Interlaboratory Comparisons |
| PTS0009 | National Laboratory Association of South Africa | Pretoria | Gauteng | Proficiency Testing By Interlaboratory Comparisons |
| PTS0010 | Thandela Proficiency Testing (Pty) Ltd | Mavhunga Village | Limpopo | Proficiency Testing By Interlaboratory Comparisons -Water Chemical Analysis |
| PTS0011 | Uganda National Tuberculosis Reference Laboratory | Luzira | Uganda | Proficiency Testing by Interlaboratory Comparisons - Medical |
| PTS0012 | Qotho Minerals (Pty) Ltd | Madibeng | North West | Proficiency Testing by Interlaboratory Comparisons |
| PTS0014 | African Mineral Standards | Modderfontein | Gauteng | Proficiency Testing by Interlaboratory Comparisons |
| PTS0015 | National Metrology Institute South Africa, Organic Chemistry laboratory | Pretoria | Gauteng | Proficiency Testing Scheme Provider |
| PTS0016 | National External Quality Assessment Laboratory (NEQAL) | Nigeria | Nigeria | Proficienty Testing Scheme Provider |
