In general, Castilian Spanish is used in IPA transcriptions. Deviations from this may occur in words with /θ/, /ʎ/ and /x/:
For terms that are more relevant to regions that have undergone yeísmo (so that, for example, hoya and holla are pronounced the same), words spelled with 〈ll〉 can be transcribed with [ʝ]
For terms that are more relevant to regions with seseo, (so that, for example, caza and casa are pronounced the same), words spelled with 〈z〉 and with soft 〈c〉 (i.e. where 〈c〉 occurs before 〈i〉 or 〈e〉) can be transcribed with [s]
In South Spain, Canarias and Caribbean countries, the phoneme /x/ (〈j〉, soft 〈g〉) is often realized as [h]
^ abcd/b/, /d/, /ɡ/ and /ʝ/ are fricatives or approximants ([β̞, ð̞, ɣ̞, ʝ̞]; represented here without the undertacks) in all places except after a pausa, after an /n/ or /m/, or—in the case of /d/ and /ʝ/—after an /l/, in which contexts they are stops [b, d, ɡ, ɟʝ], not dissimilar from English b, d, g, j, except that they are fully voiced in all positions, unlike their English counterparts (Martínez-Celdrán, Fernández-Planas & Carrera-Sabaté 2003:257-8).
^ abcdThe nasal consonants/n, m, ɲ/ only contrast before vowels. Before consonants, they assimilate to the consonant's place of articulation. This is partially reflected in the orthography. Except in loanwords and proper nouns, only /n/ (that may also be produced as [ŋ] or nasalization of the preceding vowel, depending on dialect) occurs at the end of a word.
^ abThe rhotic consonants/ɾ/ ‹r› and /r/ ‹rr› only contrast between vowels. Otherwise, they are in complementary distribution as ‹r›, with [r] occurring word-initially, after /l/, /n/, and /s/, and also represented here as before consonants, and word-finally (positions in which they vary); only [ɾ] is found elsewhere.
^Northern and central Spain still distinguish between "s" (/s/) and "soft c"/"z" (/θ/). Almost all other dialects treat the two as identical (which is called seseo) and pronounce them as /s/. There is a small number of speakers, mostly in southern Spain, who pronounce the soft "c", "z" and even "s" as /θ/, a phenomenon called ceceo. See seseo and Martínez-Celdrán, Fernández-Planas & Carrera-Sabaté (2003:258) for more information.