Rhoddwyd y cyfrifoldeb o gynnal y gwasanaeth i Lywodraeth Cymru, a hynny wedi cystadleuaeth deg ac agored, ac mae’r Gwasanaeth Caffael Cyhoeddus yn atebol i Fwrdd y Gwasanaeth Caffael Cyhoeddus sy’n cynnwys rhanddeiliaid.  Mae rhyw 76 o aelod-sefydliadau wedi cytuno i ddefnyddio’r gwasanaeth, gan gynnwys yr holl Awdurdodau Lleol, GIG Cymru, pob Sefydliad Addysg Bellach ac Uwch yng Nghymru, pob Gwasanaeth Heddlu a Gwasanaeth Tân, naw Corff a Noddir gan Lywodraeth Cymru, Llywodraeth Cymru ei hun a Chynulliad Cenedlaethol Cymru.
The Welsh Government was awarded the responsibility of hosting the service under fair and open competition, and the NPS is accountable to a NPS Board comprised of its stakeholders.  Some 76 member organisations have signed up to use its services, including all Local Authorities, NHS Wales, all Higher and Further Education institutions in Wales, all Police and Fire Services, nine Welsh Government Sponsored Bodies, the Welsh Government itself and the National Assembly for Wales.