The practical way to do it is to import the statement (in Spain, usually in the norma 43 format) and review the transactions left unmatched: that list of orphans is exactly what still needs to be booked or collected. Reconciling at least once a month keeps small mismatches from piling up until year-end close.
Rather have this calculated for you?
kontora generates your tax forms box by box, tells you how much to set aside and reminds you before every deadline.