Road tax reminder

[TameRacingDriver]

I've just had my road tax reminder through the post, telling me it is due by the end of the month. Thing is, my tax disc says end of next month. I've checked and the reg number on the ta disc is correct. When I told my dad, he seemed to think that it is "very unlikely" the DVLA got it wrong, and that my tax disc must have been a fake. Why though, would someomeone go to the trouble of producing a fake tax disc for just one month later?

Still, I suppose that means I've got to ring them up at my expense because I'll get fined otherwise?

This happened to anyone else?