Should I cancel an unused credit card?

Greveson

I've read the [url=]MSE guide on this topic[/url] but it hasn't really given me a definitive answer (due to the unsure nature of credit risk calculation). So I hope maybe a more specific case will be attract a more specific answer.

So my situation is thus: I have a current account with Lloyds. When it was a student account a bank advisor convinced me to open a student credit card. I've always been good with money so never had need for one, but his talk of online payment protection convinced me, so I let him click the button. However when it arrived I'd changed my mind, so never bother activating the card or using it. But it is still visible in my online banking.

Fast forward to now, I still have the Lloyds account, (but it has since become a Graduate account, and then a Club Lloyds account). I also have a Capital One Credit card which I opened as it provides cashback, and I thought it was time I started creating a credit score.

So my question is, should I cancel the Lloyds credit card or just leave it unused? I have no intention of using it, and don't need any extra credit. I have no debt (not counting student loans) and don't foresee myself ever having any (other than a mortgage sometime in the future). The only thing that has stopped me from cancelling it thus far is lethargy.

What are the reasons for cancelling, and the reasons for keeping it open? Any advice would be appreciated.