The Electronic Service Invoice (NFS-e), just like the NF-e, is a tax document that only exists digitally and replaces traditional printed service invoices.

It aims to document the taxable events of the ISSQN – Tax on Services of Any Nature – through the electronic recording of services rendered subject to ISSQN taxation, and was also created to enable communication between the service provider and the city government, allowing integration and information exchange between taxpayers and municipalities, reducing costs for both the taxpayer and the municipality, increasing ISS tax-collection control, and making oversight easier.
Developed by the Federal Revenue Service and the Brazilian Association of Capital City Finance Departments (Abrasf), and implemented by the Municipal Treasury Department, the NFS-e simplifies life for service providers, citizens, and businesses in the city,
The NFS-e is the municipality's responsibility, since it must provide the auditing and authorizing environment for the electronic document. NFS-e authentication happens by sending the Provisional Service Receipt (RPS) XML to the city's webservice. If the data is correct, the RPS is generated and the communication is complete.
The NFS-e connects the service provider — who needs to issue the invoice to the customer —, the City government, and the software that handles communication between the parties, like TagPlus, where issuance is very fast: you just fill in the invoice details, load the tax data with the system's help, and send the invoice. And if you need to cancel an invoice you already sent, it's even simpler — just select the invoice and request cancellation with one click.
Each municipality has its own regulations for printing formats, and it is up to each municipality to decide how to implement the NFS-e

The NFS-e is mandatory for:
Issuing the NFS-e can be optional for other sectors; however, once a service provider opts to issue the NFS-e, they can no longer withdraw that choice and go back to issuing conventional invoices
The NFS-e brings benefits to everyone involved. Looking at more specific benefits, we can mention some for those who issue the NFS-e and for those who receive it. Let's take a look:
The service recipient can use the following percentages of the ISS collected as a credit toward up to 50% of their IPTU (property tax):
You can try TagPlus software for free for 7 days and start issuing your NFS-e right now! Take advantage!