A1 digital certificate: what it is and how to install it
A1 or A3? Where to buy it, how to install it in your ERP, and why it's the key that signs every invoice you issue.
The digital certificate is your electronic signature before the tax authority. Without it, no invoice gets authorized. The good news: once it's installed, you'll hardly ever think about it again.
A1 or A3?
- A1: a file (.pfx) that lives on the server/system, valid for 1 year. Ideal for automatic issuing — the system signs on its own, 24/7.
- A3: lives on a physical card or token. More secure for occasional use, but terrible for automation, since it requires the device to be plugged in.
Recommendation
If you issue invoices all day long — storefront, POS, e-commerce — the A1 is the way to go. It lets the system sign every invoice without anyone having to plug in a token.
How to install it in your ERP
- Buy the A1 from a Certificate Authority (Serasa, Certisign, Valid, etc.).
- You'll receive a .pfx file and a password — keep both safe.
- In your system, open the tax settings and upload the .pfx along with the password.
- Done: the system starts signing every invoice automatically until the certificate expires.
In Diapasão, this upload is done once in the tax settings, and the system warns you well in advance when the certificate is about to expire — so you're never caught off guard in the middle of a sale.
Keep reading
NF-e in practice: issue your first invoice without errors
From the certificate to the authorized XML, the step-by-step guide to issuing NF-e and NFC-e without getting rejected. What each field means and where most people slip up.
Simples, Presumido, or MEI: the right tax regime for your store
Your tax regime determines how much tax you pay and how your invoice is issued. A quick map so you can talk to your accountant knowing exactly what's at stake.