You can renew your customer’s Maintenance for the new year in the period January 1st of the year you want to renew for and until January 31st of the year you want to renew for (for 2017 it will be January 1st, 2017 until January 31st, 2017 and so on.)
To see the pricing for your customer's Maintenance for the next year, please log into the portal https://portal.boyum-it.com and click on "See Maintenance 201x" in the left menu.
Those numbers reflect a forecast for your customer's maintenance for for the upcoming year. Of course the maintenance prices are subject to change if customers purchase new licenses until year-end.
If you do not have a login, please contact an Admin at your site to get one created. If you do not know who your internal Boyum Portal Admin is, please contact firstname.lastname@example.org and we are happy to help.