810L is correct (same as mine) regarding the W1, have you just started a new job? Checked the revenues website and found this on emergency tax codes it mentions W1 there.
On another page regarding tax codes it does say that L can be for normal personal allowance tax payers (e.g. me, been employed for... 18 months~) and also for emergency tax.
Edit: Beaten with a stick, check the link though and yes you will get the money back if you have overpaid (which seems to be the case), be best to talk to your employer about that.
Thanks mate. Nearly a third of my wages going out the door on taxes is insane, coming up to Christmas and that.