Questions of Cash: I need to track down any unwanted payment protection insurance over the last decade

Q. I have taken out about 10 loan and credit card agreements in the last decade. Whenever I was asked whether I wished to take out a PPI [payment protection insurance] policy, I always declined.

However, I now read that in many cases PPI was simply added on to the agreement without the borrower being asked, or made aware of it. I have now lost track of all the agreements I entered into. Is there a simple way of finding out which loan providers I used? I thought about using a claims management firm, but they typically charge a quarter of anything they recover. SE, by email.

A. There is nothing that the claims management companies will do that you cannot simply do yourself. A good place to start – and where the claims management companies would also probably begin – is to look at the credit reference files held by Experian, Equifax and CallCredit. Between them, these agencies should hold basic details of all your recent loan and credit card agreements. James Jones of Experian explains: "The credit reference files will show any credit agreement in the last six years. It won't include the agreement numbers, but people will be able to obtain those from the lenders."

Most agreements will be shown across all three agencies, though there may be some variations – not every lender uses all three agencies. You won't be the only person using credit reference files for this purpose. Mr Jones says: "We know that we are getting a number of enquiries relating specifically to PPI." Once you know which agreements you had in place, you can write to the lenders to request details on the contracts, including whether they included PPI.

You should also check your own files for the names of any older agreements – you may need a copy of the agreement in order to make a successful claim for a contract which is over six years old (providers are only required to retain their files for six years). If you find that you did pay for PPI without authorising it, we suggest using the Which? pro forma letters for making a claim. Details are available online at www.which.co.uk/campaigns/personal-finance/the-ppi- campaign/claim-back/.

Q. I am a full-time student and so am eligible to purchase an annual student Railcard for £28. But I would like to obtain a three-year student Railcard. I am not allowed to do this because I am a mature student, aged over 25. I am enrolled on a full-time, three-year course at the University of Central Lancashire in Preston. The three-year Railcard costs £65, much cheaper than buying three annual Railcards, which currently cost £28 each – £84 over the three years. Also, the three-year Railcard can only be purchased online – and only 16- to 25-year-olds can buy Railcards online! Mature students must purchase Railcards at train stations each and every year while we are studying. Why should our age deny us access to a three-year Railcard? NK, Warwickshire.

A. Atoc – the Association of Train Operating Companies – tells us that there are two reasons for this policy. Younger adults are entitled to Railcards because of their age, not their educational status, and it is concerned that mature students may not complete their courses and so hold Railcards for which they are no longer entitled. A spokeswoman for Atoc explains: "Mature students who are over the age of 25 and in full-time education are eligible for a 16-25 Railcard.

However, mature students need to confirm that they remain in full-time education, which is why they can only buy a Railcard for one year at a time. They can do this by getting the mature student section of the application form endorsed by their college or university and showing a current NUS photocard or college/university photocard with their application. This is different to applicants who are aged 16-25, as they are eligible for the Railcard because of their age rather than their status as a student."

Atoc adds that mature students and those aged nearly 25 are in a comparable position in terms of using Railcards after the age of 25. "Customers can buy a three-year, 16-25 Railcard up to the day before their 24th birthday, meaning that they can continue to use it up to just before their 27th birthday. This is consistent with a customer who is a mature student buying a one-year Railcard the day before their 26th birthday, meaning that they can also use it up to just before their 27th birthday.

In addition, there is no upper age limit on a mature student who meets the qualifying criteria, so someone of any age could get one if they are studying full time." Although mature students must at present buy their Railcards from a staffed station ticket office, or National Rail-licensed travel agent, from the middle of this month they will also be able to buy Railcards online – but still only for one year at a time.

Q. I have just realised that I don't need separate phone lines for broadband and voice. I have asked BT if it can transfer my broadband to my voice landline, so that I pay for only one line rental. In August, an engineer told me he would sort this out and arrange a refund for the prepaid rental on the redundant line.

The change took place at the end of August, but in mid-September I checked and found that the redundant line remained live and I was still incurring charges on it. I spoke to BT's customer services, who assured me it would be resolved within 48 hours and that I would be called back to confirm that this had happened – but I heard no more. I spoke to them again later and was told it had been referred to an adviser to sort out, but the situation remains the same. AM, Birmingham.

A. BT has now closed the redundant line and apologises for the delay in resolving this. It is crediting your next bill with £30 as a goodwill gesture.