total time to remain in on Tier4

[Princess of Ammi]

scenario
a student came in to UK in September 2010 and undertook level 5 that she finished in December 2011. she then enrolled herself for level 7 that she started in Jan 2012 and finished in December 2012. she then enrolled herself for Postgraduate degree at university that she stated in Jan 2013 which she will finish hopefully in Dec 2014 (dissertation submitting is in Sept. 2014).

her visa is valid until April 2015 where she on completion of her on-going course that she finishes in September 2014(dissertation submission) officially in Dec 2014(result out), wants to undertake PhD that she is confused on total time a student can remain in on tier 4.
a PhD typically takes 3 years to complete while the time she has been in UK on tier 4 by the end of her current course will be 4 years in total 3 years of which she spent doing level 7 diploma and degree.

can anyone answer if she has 3 more years for PhD if she starts that in Sept. 2014? and
how long does she have in total to remain in the UK on tier 4 where she wants to do higher than postgraduate level 7 degree?

[riz1986]

In total she can spend 8 years on tier 4 visa.So she can get in admission in PhD and continue study until she reaches 8 years and after that full stop.She might need to switch into an other category if she wants to stay in da country.