Well when I saw this question I thought that is a strange one as in the UK the Tax Return is the form you fill in with all your details for the year and you send it off and if you don't you get in trouble, so my answer would have been to send it off! But I guess it means what we would call a tax refund? If so then I would do what the experts say with any spare money and pay off debt with the highest level of interest, e.g. credit cards. If you don't have that kind of debt (lucky you!) then yes, invest in some tax free savings plan, no idea what kind of plans there are outside the UK!