Compostela and a multi year Via de la Plata

You can walk over several years if you wish - many people do and receive a Compostela at the end. As far as qualifying for a Compostela is concerned only the final 100km is actually required and even that need not be walked in one continuous journey. Perhaps @t2andreo can advise on what the distance certificate would say in your case?

I walked the Via de la Plata in three parts in 2008-2010. In the pilgrims office we showed our credencial documenting our pilgrimage from the beginning in Sevilla and obtained our compostela. But they noticed that we had walked the whole way and thus in mass we were introduced as 3 german pilgrims arriving from Sevilla. So I expect, that the certificate of distance will refer to your original start but count all days since then (inclusive the interruptions).

BC
Alexandra