Clitic doubling (CD) is the co-appearance in the same sentence of the clitic and a correlative syntagma in the canonical position of the object. Apart from obligatory contexts, CD of the indirect object (IO) is found with variable frequency in Romance languages and even in different varieties of the same language, most likely because it is a phenomenon of internal/external language interface. The objective of this work is to determine the frequency of CD in non-obligatory contexts of recipient and location IO in peninsular Spanish, and to analyse its features according to the referential hierarchy used for the diachronic evolution of the phenomenon. For this purpose, we extracted data from two open access corpora of interviews (COREC and PRESEEA) from different regions that are (or are not) areas of historical contact with other languages. The results show a significant extension of doubling in contexts where this is optional and the neutralisation of features that previously predicted CD of IOs. Nevertheless, there are geographical differences in peninsular Spanish in terms of frequency, definiteness, specificity, the influence of the cliticization of the direct object, and the accessibility of the IO referents in the minds of the speakers.