Is this a scam?

Hi I’ve just received the following text that I’m pretty sure it’s a scam as I’ve not signed up for anything other than my mobile package over a year ago or there abouts: 

“You signed up for SMS from shortcode 60551. You've insufficient funds to receive it so need to buy an add-on. Visit https://info.smarty.uk/c9i8x1x9 for details.”