As you say your son is at uni between terms and is or has been in receipt of a student grant ... then it's very unlikely they are elligible for JSA or any benefit as they are returning ie full student. To be elligible for JSA you must be looking for work on a full time basis. For every full time student it is the same. So, technically no you are not elligible to claim it between terms.
When you complete the form - which is usually done over the telephone now, but you CAN ask for a written application form; don't let the JCP staff fob you off, which they will try and do, but you can complete a written form - they will ask you and go into depth on your circumstances. It will just take a little longer, though, as DWP also uses the evil call centre now to save on money. Plus, they'd automatically ask what you've been doing for the 12 months or less eg whilst being a student. So, he'd have to tell them anyway and what his plans were. Also, there is a good chance they will check with the uni whether he is intending to return next term.
Here is an extract from a place your son can go to to get further advice on this. It's called Connexions, specifically aimed at younger people it's like a CAB aimed at that age range but much more:
Who is eligible for Jobseekers Allowance?
Jobseekers Allowance is available for those over the age of 18 who are capable and available for work and actively seeking a job.
A Jobseeker’s Agreement is agreed with an adviser at the local Job Centre, covering the type of job you are looking for and how you will try to get work. You will have regular follow up interviews to discuss your job search progress. Your benefit depends on you proving that you are actively looking for work and doing as you agreed in your Jobseeker’s Agreement.
Full-time students are not usually able to claim Jobseeker’s Allowance. Part-time students may be able to claim if they are available for and actively seeking work. They must also be willing to change the hours they study or give up their course immediately to start a job.
16 and 17 year olds are not usually entitled to Jobseeker’s Allowance as the government has guaranteed a Youth Training Place to all. However, certain groups are able to claim. These include:
- People with a partner and children
- People with disabilities
- people who have just left care or prison
- Young people forced to live away from home.
He can either take the risk, apply ... then get caught out at the application stage ... Given the structure of the DWP right now, not a good idea. It will have repurcussions for any future claim as well. Or find out where your local Connexions centre is. His student union, at the least, should have info on one as they work closely in conjunction with local universities and colleges.
The general consensus - and unless DWP has altered radically since I was a uni student, which I doubt; in fact, they've tightened up, made things harder - is no, you can't claim between term times. Whilst on that subject, though, it doesn't nor hasn't stopped teachers from claiming in the summer breaks an array of benefits ... makes you think, doesn't it?
However, if your son pays a visit or finds out from the place I mentioned ...
Connexions may also be able to offer or suggest other financial aids in the short term between terms.
University and benifits 
