When to purchase e-NP314
e-NP314 is licensed differently to other e-NPs.
e-NP314 is an annual publication, and new editions are normally published each April in the year before the data becomes valid. As an example, e-NP314-17 was published in April 2016.
When e-NP314 is purchased, it is licensed for two years (24 months) and is not replaced when a new volume of e-NP314 is published. Each edition of e-NP314 is a standalone product, and unlike other e-NPs, it is not replaced automatically within the subscription period. Instead, a new copy of e-NP314 should be purchased each year.
e-NP314 is provided for 24 months to allow the replaced edition to be used as a historical reference for a year after it has been superseded. This allows users to continue using the older edition when referring to calculations they have made using the data it contains.