Formally validate Billing Details

[Kian]

Last week I decided to start working on a project that I think that nobody ever wanted to do... me included 😭 but I can no longer stand this issue: fomally validate Billing Details. I'm creating a system that validates Billing Details depending on economic zones (Intra-EU, Extra-EU and specific countries), entity (invdividual, company, organization, public authorities, government), local laws and Revenue Agencies. Right now I'm working on these goals (✔️ = done)

• Individuals from Italy. Codice Fiscale (aka Tax ID) is mandatory and must be formally valid (16 characters, firstname and lastname matching the first 6 characters of Codice Fiscale) ✔️
• Companies from Italy. Partita IVA (VAT Number) is mandatory and must be formally valid (11 characters, numbers only, valid security number). Codice Fiscale (Tax ID) is also mandatory and must correspond to Partita IVA. Codice Destinatario for Electronic Invoicing is also required and must be valid (PEC address, SdI code 7 characters or PA code 6 characters) ✔️
• Sole proprietorship or sole professional from Italy. Partita IVA and Codice Fiscale are both mandatory and must be valid. Codice Destinatario is also required and must and must be valid (PEC address, SdI code 7 characters or PA code 6 characters) ✔️
• Organizations, Public Authorities, Government from Italy. Codice Fiscale is required and must be formally valid. Partita IVA is optional but must be correct when specified ✔️
• Intra and Extra EU individuals. Tax ID (passport ID should be allowed) is required ✔️
• Intra-EU companies. VAT Number required and formally valid according to formats of each Revenue Agency of Europe (long to do but viable). Tax ID is optional ❌
• Extra-EU companies. VAT Number is required. No further checksare  required ✔️

Am I missing something? I have no experience with other countries therefore I'll need some help. Before you ask, VIES has nothing to do with what I'm trying to achieve here. I check VAT Numbers separately in other ways. I just need to validate details formally.

Edit: nice, I think I posted in the wrong section 😩

 

Edited December 4, 2018 by Kian