In the case of a business, we remind you that in the unique additional provision to the Order HAC/3134/2002 (BOE of December 13, 2002)
"Business owners or professionals that use electronic and information technology means to manage billing, accountancy and the generation of fiscally binding books and records must save the files, databases and programs required in a magnetic or optical medium for the prescribed period to allow full access to them for the purpose of correctly tracking them."
Electronic bills are completely legally and fiscally valid. In the event that you lose your digital copy of a file and you don't have a backup, you can download your bills again from Endesa Online
. Remember that you can consult your bills for a period of 5 years.