no problem! Think it's until the end of November at least. When you fill in the application form, (at the www.worldpayzinc.com site), there is a bit that says 'do you have a referral code, I believe on page 5, and you pop it in there. To reiterate, they don't charge you until the 18th of the next full month for the chip and pin and any sales percentages.
:-)