In Italy, an electronic invoice goes from the seller to the buyer through the SdI (Sistema di Interscambio), the Agenzia delle Entrate's exchange system. The SdI delivers it to the buyer's recipient code or PEC address, and the Agenzia can keep a copy for you to consult in the Fatture e Corrispettivi portal.
Where to find received invoices
Sign in to Fatture e Corrispettivi with SPID, CIE or CNS. Under consultation, open the electronic invoices and choose the received ones. Filter by the date the SdI delivered them and download each file in XML, or as a readable copy.
The consultation service must be activated
The portal only keeps the full files for taxpayers who have joined the consultation service (adesione al servizio di consultazione), once, in the same portal. With it, the files stay available until December 31 of the second year after the SdI received them. Without it, the Agenzia deletes the file after delivering it and keeps only the invoice data, such as the parties, the date and the amounts. Joining is free and can be withdrawn at any time.
Accountants and software
An accountant or software provider can consult and download invoices for you once you have given them a delegation in the portal.
Private individuals
A consumer can join the consultation service for invoices received, from the reserved area of the pre-filled tax return.
Receipts are a different flow
A shop's receipt (documento commerciale) is not an invoice: the register sends the day's totals to the Agenzia (corrispettivi telematici), not each receipt with its items. If you give your codice fiscale at the till, the receipt can be used for personal deductions, but you still keep the paper.
Keeping the receipts
Smartbills keeps the receipts the SdI never sees: photograph a documento commerciale in the app or forward the email from an online shop, and each one is kept with its items, every tax and the total.