The PhD (Doctor of Philosophy or simply 'doctorate') is internationally recognised as the most advanced academic degree, requiring original, independent research. PhD students produce an extensive dissertation, which should make an original contribution to knowledge in the field of study. A PhD usually takes at least three years of full-time study. A wide range of programmes is available at British Higher Education institutions.

There is also a new type of PhD available, called the new route PhD. This has been developed by a consortium of ten leading English universities and is supported by the British Government and the UK's national research, quality and funding agencies.

The new route PhD is different because it offers an integrated approach to studying for a Doctorate; this combines a specific research project with a coherent programme of formal coursework and professional skills development.

Iranian postgraduate students with good standing from a university recognized by the Iranian Ministry of Science generally qualify to submit a research proposal for PhD programs in the UK.