It is actually the INTERMEDIARY CODE (formerly known as the Univocal Code) which is issued upon request if an intermediary is delegated to manage electronic invoicing. So if you subscribe to a replacement storage service with Aruba, Register.it, keliweb.it, 2cSolution, infocert, etc., you will receive your INTERMEDIARY CODE - an identifier of 7 - to be communicated to your suppliers. In fact, only subjects with a transmission channel already accredited with the Exchange System to receive electronic invoices will be able to request it.
Notes : also the free replacement storage of the Revenue Agency - Invoices and Fees - allows us to have our RECIPIENT CODE : https://bit.ly/2Cir4Vq
Subscribing to a system for replacement storage is practically mandatory if you want to avoid sending and archiving our invoices manually and for free on the Revenue Agency system , to keep in mind that the deadline for archiving invoices is within the third following month on the date of the planned dispatch of the tax return of the reference year. From 2018 the storage deadline should be 31/12/2019 since the deadline for UNICO / 19 should be 30/9/2019.
The PEC is still sufficient. To check our PEC or find that of one of our customers, we can use the InfoPec service at the following address: https://www.inipec.gov.it/cerca-pec