They won't love you for it - 25p min, and at least 9p/min afterwards, and that's from landlines.
Not included in packages, and much more expensive from mobiles.
For some reason, I had it in my head that 0560 numbers were like normal NGN numbers and included.
So be nice to your customers and get a geographical number - for the sake of a couple of quid per month, it'll save a lot of hassle!
Just be aware of that before you find yourself on the wrong end of grumblings.
PS - loving Voipfone in all other aspects :)