B+E Licence... What can I tow?

[TAHodgson]

Hi everyone, i've been looking at doing my B+E for a while now (I'm only 23, so new licence, no grandfather rights..) so I can tow my race car around without depending on my Dad to do it for me. I've had a chat with a local to me company who can do the tuition and arrange the test for the best price i've seen so far. When speaking to them on the phone, I asked "Once i've passed, what weight am I legally allowed to tow?" to which their response was "Whatever the maximum towing weight for your vehicle is".
Now I know that a good general rule is only to tow 80% of the maximum, but can someone please confirm this?
EG: Land Rover Discovery max. braked towing capacity is 3500kg, if I were to use said vehicle and tow 3500kg would I be legal?

Apologies if this seems like a silly question, but as i'm sure you're all aware... towing is a bit of a minefield.