WHMCS Vs. SIDN & Denic
As most users know, and most definitely users who register .NL & .DE domains through WHMCS, WHMCS only knows annual periods for invoicing domains.
.NL (SIDN) & .DE (Denic) domains have the possibility to be either registered/renewed for 1, 3 or 12 months. On the images below is specified what the exact numbers per TLD are.
Both the TLDs above are the only TLDs who offer these periods for registrations/renewals. Since WHMCS only knows annual invoicing periods, this can cause inconsistencies between the expiry date in WHMCS and the actual expiry date at the registry, and it will cause domains with a smaller period than annual to be excluded from the domain sync in WHMCS.
There is no option to automatically update the autorenew period for .NL & .DE domains to an annual period in the Realtime Register WHMCS module. We do, however, ensure that all transfers and creates through WHMCS are forced to an annual period and auto_renew is set to false for the domain as soon as it enters your Realtime Register account. In order to change the autorenew periods in your Realtime Register account for .NL and .DE domains, Changing auto renew periods for .NL & .DE knowledge base article.