What can I do about it?
While there is no quick fix, there are things you can do to build it up. First off, get a credit score report and double check that there are no mistakes that could be lowering your score.
However, if the facts don’t lie, the more you can do to show that you’re a responsible borrower, the more likely you are to start improving your credit rating. Doing so reduces your chances of being refused for credit cards, loans or mortgages.
One way of doing this is to take out a credit builder card. This is a special kind of credit card for people with bad credit ratings. They can be a great first rung on the ladder to building (or rebuilding) your score.