Instructions:Use Code: BOOZAZZLETEE
Taken from the site:
"Halloween Sale - 10% off T-shirts! Use code: BOOZAZZLETEE (Ends Sunday)
10% of the t-shirts net sale price will be deducted when one or more qualifying t-shirts are purchased and the coupon code BOOZAZZLETEE is applied at checkout. The net sale price is the price of the product (excluding shipping and taxes). Offer is valid from through November 31, 2010 at 11:59pm GMT. This offer does not apply to past purchases and may not be combined with any other Zazzle promotional or volume discount offers. If a volume discount applies to your order, you will receive either the discount set forth in this offer or the standard volume discount, whichever is greater. Offer valid on Zazzle.co.uk only."