Great news for British nationals living in Spain who need to renew their passports or apply for a new one for their child, there is a 35% reduction in fees for people applying from overseas. This equates to a significant saving of £45 for adults and £28.50 for children, made possible by efficiency savings made by closing down the Madrid passport processing centre and bringing the service back to the UK, amongst other things.
You can renew or replace a passport or apply for a new passport for your child using the really useful Gov.UK website, it takes three weeks to get a new passport, longer for the first passport for a child. Visit this page https://www.gov.uk/overseas-passports and it will walk you through the stages of the passport application. You can download the form and send it with all the required documentation to the UK for processing and you can track the process online as well.