Of the two options we would recommend Kia as one of the most reliable brands you can buy. Your budget of £15,000 means you're limited to the Picanto if you're buying new, but it is an accomplished small car and if it's big enough for your needs then it is a smart choice.

Buying new also means you benefit from the full seven years of warranty, but if you need something bigger then an approved used car would give you a bit more choice and still benefit from a lengthy warranty. A quick search turned up a few examples of the Kia Ceed within your price bracket, which would give you a bit more space and excellent reliabilty.