Mathematical models were used to explore the conditions under which a coupon provides a conservative assessment of the level of cathodic protection provided to holidays on coating buried structures. The most
conservative assessment of cathodic protection was obtained when the area of the coupon was larger than the area of the largest expected holiday. The performance of the coupon as a monitor of cathodic
protection was found to be strongly influenced by the availability of oxygen in the soil. Keywords: coupon, cathodic protection, pipeline, corrosion