School of Mathematical and Physical Sciences



Online registration opens each year on 1 September.

New students: you will receive an email from the central University team with instructions for registration before you arrive at Sussex. 

Returning students: your registration will end every year on 31 August, you need to re-register in September. To be permitted to re-register, you  must have passed your Annual Progress Review (Thesis Committee). See Progression for more information on this process.

Changes to your registration status

A number of situations may occur where you need to change the way you are studying.  An outline of the main registration status types can be found below. Full information about the key stages and processes that occur throughout a research degree can be found here: RSAO/research degree


When you have completed your lab work, you can transfer to pre-submission status (aka 'writing-up'). This is optional. This status is commonly used by students whose funding ended at 3 or 3.5 years because tuition fees are greatly reduced as you no longer use the lab.  

Supporting documents:

  1. A detailed timeline and plan for the period to submission, which should include description of any research that needs completing, details of any papers you plan to write, specific dates of submission of chapters to your supervisor for review, time for revisions and a contingency.
  2. Statement of support from your main supervisor.

Further details and application forms can be obtained from RSAO.


If unforeseen circumstances have significantly delayed your progress and you will not be able to submit your thesis by your deadline, you can request an extension. This has been more common in light of the covid-19 lab disruptions, but is usually a rare occurrence, only requested due to exceptional circumstances that were unexpected. A period of intermission should be used for extenuating circumstances that are foreseen.   

Should it be necessary for you to request an extension to your maximum date of registration, you should consult your main supervisor in the first instance. You should then complete an application form, available on the Research Student Administration Office website. If your supervisor supports your request, they will add a statement in support of the extension to the application form and make a recommendation to the Director of Doctoral Studies, who will then notify the Research Student Administration Office of the final decision. The Research Student Administration Office will then write to you to notify you of the decision.

When making your request for an extension, you should supply the following:

  • a statement setting out the reason for the request for an extension
  • a statement of the current progress of your research and writing-up
  • a timetable for the completion and submission of your thesis
  • any documentary evidence in support of the request.

Further details on extensions may be found from RSAO.


If you need a break from your studies for financial, health, or personal reasons, you can request intermission. Doing this will 'stop the clock' on your PhD so that you do not lose any time from your maximum period of registration. Intermission status is a temporary withdrawal from the university. You can intermit for a minimum of one month and RSAO will adjust your thesis submission date accordingly. 

Request a break by completing the Intermission Request Form, found here. This should be emailed to along with any relevant evidence. 

If you are funded, you need to notify your sponsor that you are taking a period of intermission so they can adjust your funding. Most Research Councils stop stipend payments while you are intermitting. 

Students with a student visa should discuss with the University’s International Student Support team first as intermission stops the university's sponsorship of your visa meaning it will be curtailed. A period of authorised absence is the alternative which does not affect your visa. However, you can only take this absence once during your whole PhD, up to 60 days maximum. More information is available from RSAO.

Speak to the School's PGR coordinator if you have any further questions. You may also find it helpful to contact the Student Life Centre who can provide advice and support in a number of areas. 

Changing from full-time to part-time or vice versa

If you want to change from full time to part time or vice-versa discuss it with your Supervisor and then submit the following completed form. International students in the UK on a student visa are not permitted to study part time and can contact International Student Support for further information.

Find the application form here

Changing from MPhil to PhD or vice versa

Your Thesis Committee may recommend this change based on your annual progress review performance. This change must be discussed with your main Supervisor before you complete and submit the relevant form. 

Find the application form here