Electronic invoices (SEF)
E-invoices from the programme, not the portal
You create an invoice once and send it to SEF, Serbia’s national e-invoicing system, with one click. Incoming invoices arrive in the programme with their PDF, and you approve or reject them without opening the portal. The status of every document is shown next to it.
Updated:
What duplo sends to SEF
| Document | Goes to SEF | Note |
|---|---|---|
| Invoice | Yes | The basic outgoing document |
| Advance invoice | Yes | With the date the VAT liability arises |
| Credit note | Yes | Linked to the specific invoice it relates to |
| Quote and proforma invoice | No | Not tax documents |
| Delivery note | No | Goes to its own system — e-delivery notes |
Connecting takes a minute
- On the efaktura.gov.rs portal you generate an API key for your company.
- In duplo you switch on “I send e-invoices via SEF” and paste the key.
- You choose the environment: demo for testing or production for real transactions.
- From that moment every invoice has a send button and shows its status.
Incoming invoices without retyping
Received e-invoices are pulled from SEF into the list of received invoices — with number, supplier, amount and status. Clicking the number opens the original PDF from SEF. Approving and rejecting are done from the programme, and a comment is required when rejecting, just as the system demands.
Credit notes the way the rules require
In duplo a credit note is issued only against a specific invoice, so the document always carries the number and date of the invoice it relates to. When the issuer is VAT-registered, the PDF carries the note required by Article 21(3) of the VAT Act and a block for the recipient’s confirmation, and the programme records the date on which the customer’s notification that it has corrected its input VAT deduction arrived. The programme also does not allow the total of credit notes to exceed the invoice amount.
Frequently asked questions
- Who is required to issue e-invoices?
- VAT-registered businesses must issue e-invoices in transactions with other businesses and with the public sector. A business that is not VAT-registered is not obliged to issue them, but it must receive e-invoices if it deals with the public sector, so it still needs to register on SEF.
- Do I need a SEF account if I use duplo?
- Yes. duplo connects to your existing SEF account through an API key that you generate yourself on the efaktura.gov.rs portal. Legally, the invoices still go out from your account — duplo is just the programme you send them from.
- What does duplo send to SEF?
- Invoices, advance invoices and credit notes. Quotes, proforma invoices and delivery notes are not sent to SEF because they are not tax documents — delivery notes have their own system (SEO).
- What if I do not accept an incoming invoice in time?
- The deadline for a reply is 15 days. If you are in the public sector, the invoice is deemed accepted once the deadline passes. If you are in the private sector, you receive a repeat notification and another five days; if you still do not reply, the invoice is deemed rejected — and a rejected incoming invoice also means a problem with deducting input VAT.
- Can I test it before going live?
- You can. In the settings you choose the demo or production environment, so you can try everything on the demo SEF before switching the key to the real one.
Further reading
Try duplo free for 30 days
No card required. Three plans by the scope of your work, from 9 € a month billed annually — everything in a plan is unlimited from day one.