We are currently in the coexistence period of CFDi 3.3 and 4.0. If you have already tried to certify a CFDi according to version 4.0 requirements, perhaps you already faced a situation that for sure will require enormous effort for the companies.
Fiscal address and Fiscal Regime change from optional to required, and according to the specifications these fields must include valid values. Initially, we could think of values included in SAT catalogs, but after some testing, we can understand the real requirement. What is really needed is to include the values that Tax Authorities have in their records.
In the commercial relationships, it means that taxpayers will need to share with all their suppliers any fiscal address changes, but the real problem is with employees since it is not common for regular citizens to notify address changes to tax authorities.
If the companies do not have the official fiscal address of the employees, the payroll CFDi cannot be certified, causing the payroll expense to become non-deductible. Additionally, if the certification doesn’t happen within the mandatory timing the company will also be subject to fines. To make this situation more complex, the fiscal address, fiscal regime, and even the name recorded on SAT records only can happen through the employee either visiting SAT offices or by remotely using some tools recently released by Tax Authorities as part of the Covid-19 response. But these tools require some savviness on the use of smart devices and email.
Considering the limited coexistence period, it is complex for the companies to comply with this mandatory condition. We can expect saturation on SAT offices and systems. So, the soonest the companies start working on this, the more ready they will be.