We will either charge or refund any differences between charges if there are differences between the online quotation and the cost of production once the full specification is confirmed. If fulfilling your order requires any special requirements or techniques, you may be charged additional costs. Additional costs may be levied for the following: Laser drill, back drill, countersunk, counter bore, edges plated, skip V-scoring, half-cutted via, vias filled with epoxy, via in pad / vias filled with copper, requirement for 100% failure free in panel, special press-fit connectors, multi-type surface finish, multi-color silkscreen or solder mask, surface finish (ENIG) area in the boards exceed standard (15 %), gold thickness exceeds standard of 1-3 micro inches, over-sized board (width size / height size 600mm or more than 600 mm), ultra small board (width size and height size are both less than 25 mm), special packing requirements, etc. Yes,they're allways recurring costs.