FAQ 779
Can I leave the UK during holiday periods?

You can travel home, within the UK, or to other countries during confirmed holiday periods without asking for permission. You must be sure of your dates of travel and that they fall within your holiday period. The holiday periods will depend on your course type and start date. The Student Information Desk (SID) will be able to tell you your holiday periods.  

Please note that if you are working on your project/dissertation or referrals, or are still attending classes, you are not considered to be in a holiday period. You should obtain a letter from SID which you can carry with you on your travels. It is important that you do this in case the immigration officials require proof of your status upon your return to the UK. This letter will contain the dates of travel. It may also be beneficial to carry proof of availability of funds, in case these are required by the immigration officer.