NFC-e at the auto shop: counter parts sales, with QR Code and CSC

The essentials

NFC-e (model 65) is the nota for over-the-counter sales to end consumers. It replaced the cupom fiscal and the ECF.
The QR Code is what lets the customer check the nota on their phone, and it depends on a secret called the CSC.
There's offline contingency: without internet, the counter keeps selling and the nota is transmitted later.
At the shop, the dividing line is simple: end consumer taking it on the spot → NFC-e; business, fleet or delivery → NF-e.

A shop that also sells parts over the counter has, in practice, two businesses under the same CNPJ. One is the service, which ends in a work order and an NFS-e. The other is pure retail: someone walks in, asks for a filter, pays and leaves. That second business has its own document.

What Promec does today in Brazil. The system runs the whole shop — AI quotes, scheduling, the mechanic's app, inventory, the customer portal and accounting — and it invoices with your own series, taxes and currency. What it doesn't do yet is issue NF-e, NFC-e or NFS-e directly against SEFAZ or the municipality: that integration is in development and we don't have a date for it. Meanwhile, fiscal issuing stays with your current issuer. We prefer to say this before you sign up, not after. Where direct integration already exists is on the coverage page.

When it's NFC-e and when it's NF-e

The rule that covers 95% of shop cases:

Situation	Document	Why
Individual customer takes the part on the spot	NFC-e	Over-the-counter sale to an end consumer.
Part applied to the service, billed on the work order	NF-e or NFC-e depending on the case	The part is still merchandise; labor goes separately, on an NFS-e.
Billing a fleet or another business	NF-e	Transaction between taxpayers; the recipient needs the XML for tax credit.
Part shipped by a carrier	NF-e	There's circulation of merchandise, and the DANFE travels with the shipment.

The CSC and the QR Code

What visually sets NFC-e apart is the QR Code printed on the receipt. It's not decorative: it takes the customer to the public lookup of the nota on the SEFAZ portal. For the code to be valid, it's calculated using a taxpayer secret, the CSC, which you request from your state's SEFAZ and register with your issuer.

Three things not to forget about the CSC

It's per state — if you open a branch in another state, you need a different one. It has an associated identifier (idToken), and the two travel together. And it's secret: keeping it in a shared file is the same as leaving your bank password at the counter.

Offline contingency: the counter can't stop

This is the most important practical difference from NF-e. At a counter sale the customer is standing right there; there's no way to say "come back tomorrow, SEFAZ is down." NFC-e provides for issuance in offline contingency: the document goes out marked as such, the receipt is printed, and transmission happens once the connection returns, within the set deadline.

When evaluating a system, the question is literal: with the network cable unplugged, does the counter keep issuing? If the answer is no, you'll find out on a Saturday morning.

Printing: less equipment than you'd think

The ECF died with NFC-e. A regular thermal printer does the job, and the receipt is smaller than the DANFE because the document is leaner. In several states, if the customer agrees, you don't even have to print: handing over the key or the QR Code by message is enough. At a shop this fits well, since customers are usually already in touch over WhatsApp.

The blind spot: inventory

NFC-e is quick to issue, and that's exactly where the problem lies. When the counter sells without deducting inventory in the same movement, the physical count stops matching the system's within a few weeks, and from there no margin report is worth anything. The fiscal document and the inventory movement have to be the same act, not two tasks someone remembers to do.

It's the same principle as with NF-e: the nota is the last step of a process, and its quality is the quality of the records behind it.

Sources

National NF-e Portal (nfe.fazenda.gov.br), Manual de Orientação do Contribuinte, Ajuste SINIEF 07/05 and technical notes published by ENCAT, state SEFAZ portals and municipal ISS legislation. This text is informational and doesn't replace your accountant's guidance: the rules vary by state and municipality and change often.

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FAQ

What's the difference between NF-e and NFC-e?

NF-e (model 55) is for transactions between businesses and for sales with delivery, and the DANFE travels with the merchandise. NFC-e (model 65) is for over-the-counter sales to end consumers: the document is leaner, the printout is a receipt with a QR Code, and the customer looks up the nota on their phone. At a shop, a part sold over the counter usually goes on an NFC-e; a part billed to a fleet or another business goes on an NF-e.

What's the CSC, and why do I need it?

The CSC — Código de Segurança do Contribuinte (Taxpayer Security Code) — is a secret code you request from your state's SEFAZ, and it's used to calculate the NFC-e's QR Code. Without a valid CSC there's no valid QR Code, and without a valid QR Code, the nota isn't usable. It's a configuration value you register once, but it needs to be kept as carefully as a password.

Do I need a fiscal printer or ECF?

No. NFC-e did away with the ECF. A regular thermal printer is enough to print the receipt, and in many states printing isn't even mandatory if the customer agrees to receive the nota another way, like a QR Code on screen or sent by message. That significantly cuts counter costs compared to the old model.

What if the internet goes down with the customer standing there?

NFC-e provides for offline contingency: the system issues the document with a specific marking, prints the receipt, and transmits the nota to SEFAZ once the connection comes back, within the deadline set by the state's regulation. It's the difference between continuing to sell and telling the customer to come back tomorrow. Confirm the deadline that applies to your state.

Does NFC-e apply the same way in every state?

NFC-e has been adopted by every state, but the detailed rules — contingency deadlines, whether printing is mandatory, value limits for identifying the consumer — are set at the state level and aren't identical. Before configuring anything, confirm your state's rules with your accountant.