Acceptable to do significant work on PhD before officially starting? This question concerns PhD programs that, unlike most U.S. programs, don't start with a 2 year coursework program. That is, programs where you're expected to do a 2 year master before the PhD and then finish your PhD in about 3 years consisting solely of research. Let's say this concerns a PhD program at Oxford or Cambridge, UK.

I came to this question after reflecting on the fact that some PhD students finish their PhD in significantly shorter amount of time than average. I thought: What if we carry this to the extreme:

Consider the following scenario: Let's say that after obtaining a master's degree, a student spends 3 years working independently on their own research, and produces papers that in amount and quality would be sufficient for obtaining a PhD. Would it be acceptable for this student to simply register for a PhD program, and immediately hand in this work?


In this way, the student is registered for the PhD program for only a very short time (the time required to hand in the work, and do the thesis defence). Therefore presumably the student has to pay tuition only for this short period rather than for 3 years.


This question is not about whether trying this is advisable, but solely about whether universities will accept this.
Your question is based on a false premise.

In many countries (virtually all?) where the nominal PhD duration is 3 years, students are actually paid during their PhD, through a scholarship or a salary, and there is no tuition at all or a minimal one.

It doesn't make any sense, thus, to spend 3 years working independently, with no support from the adviser and for free.

Whether that would be accepted is highly dependent on the country or on the specific university regulations, and we cannot give a general answer. It seems that in my country, Italy, it was once allowed, but now it is no longer possible, by law (I didn't check very carefully though).