README

Vatfallback module provides an API based validation and a fallback offline regex validation for the unstable VIES database used by Magento

Supported services

VIES check (this is the official endpoint but not the built-in Magento version)
vatlayer.com check
Regex fallback check for following countries; AT, BE, CZ, DE, CY, DK, EE, GR, ES, FI, FR, GB, HU, IE, IT, LT, LU, LV, MT, NL, PL, PT, SE, SI, SK
Caching of previous results

A plugin that replaces the existing VAT check in Magento Customer implementing various services with means of fallback.
Use the console task: ./bin/magento vat:validate NL NL133001477B01
Use the API endpoint to get company data by VAT number http://domain.com/rest/V1/vat/companylookup/NL133001477B01
Add a GraphQL endpoint by installing elgentos/m2-vatfallback-graph-ql
Caching service for VAT request (be sure to enable the VAT cache under Cache Management)

composer require dutchento/m2-vatfallback
bin/magento setup:upgrade

Warning: Since all of the free VIES API's are slow and somewhat unreliable the checkout steps could become slow while checking.