You do not have any obligation in case u accept an offer. Why do you hesitate?
I quote QMUL :
"Once we have offered you a place on a programme of study or research, setting out any conditions associated with the offer, and you have accepted it, you have entered into a legally binding agreement with QMUL. If you want to withdraw from this agreement and cancel your acceptance of an offer, you must notify us within 14 days of the date that you accepted the offer:
For applicants applying to us through UCAS, this means 14 days from the date that you accepted the offer as your Firm or Insurance choice in UCAS Track.
For applicants applying directly to QMUL, this means 14 days from the date when you accepted your offer in your online portal.
You must let us know in writing of your decision to cancel the acceptance of your offer. Once you have done this, your offer of a place on the programme will be withdrawn".
They don't give further details in case you want to withdraw after these 14 days ...
I suppose the offer is binding ...
Did someone e-mail QMUL asking if there is a fine or something?