RE: 18 digits reference number of volunteer NI contributionsLike others above I only require an 18 digit number in order to pay a lump sum of voluntary national insurance. I've tried many times, been on the phone over an hour and then cut off. Managed at one point to speak to someone, purely as I'd inadvertently given wrong info, or the automated lady thought so, sadly it was way over an hour and my landline battery gave up on me - how annoying is that. I've tried several other times, stayed on phone over an hour, been on phone many, many times, and then cut off, often. Its certainly not a very polite system though expect its due to high volume. I am frustrated I cannot get hold of someone to acquire the relevant 18 digit reference number (I've looked at the site and can't see another way, other than sending a cheque and covering letter and have no reference to put on that albeit my NI number. I anxious to get this sorted as I retire early May. As everything else is in order and its just a case of a 'elusive' number its very frustrating to say the least. All I can do, alongside many others, is keep trying and ringing and getting cut off, time and time again, until, hopefully, one call will give me success to speak with a person and get the relevant number.