A fiscal register on a phone or tablet: what the law allows, what you need and where the limits are

"Fiscal register on a phone" is among the most common searches in Serbia, and the reason is obvious: you already own a phone, while a dedicated register costs money and takes up the counter. The question is whether it is allowed and what exactly it has to do. The answer is that it is, not because a phone is special, but because the law does not look at the device at all.

What the law actually requires

Article 2 of the Law on Fiscalization defines an electronic fiscal device as a "hardware and/or software solution". The word "or" is the key: the device does not have to be a box. The ESIR, the part the cashier types into, is defined just as broadly, as a hardware or software element. An app on a phone, a web application in the phone's browser or a program on a tablet are, in that respect, equal to a dedicated register.

What is not optional is approval. Every ESIR, whatever its form, must pass the Tax Administration's technical review and be entered in the Register of approved elements. An app that is not in that register is not a fiscal register, however it looks. The register is public; check the product by name before you install it.

Three things the phone must have

1. An approved ESIR

That can be an app from an app store or a web application that opens in the browser and, if you like, installs on the home screen. Legally there is no difference. Practically, a web application has one advantage: it is the same on a phone, a tablet and a computer, so when the counter outgrows the phone you do not change registers.

2. Access to a PFR

The phone does not sign receipts itself; the PFR does. With the Tax Administration's V-PFR the phone needs internet, mobile or Wi-Fi, at the moment each receipt is issued. With an L-PFR the phone connects over the local network to a processor on the premises that holds your card in a reader; an L-PFR on the phone itself is rare in practice, because it usually needs a card in a reader. If you need to sell with no connection at all, that is the setup with an L-PFR on the premises and a phone on Wi-Fi: Does a fiscal register work without internet.

3. A way for the buyer to get the receipt

The law requires the receipt to be issued to the buyer, and in printed form (rulebook on receipt types, Article 13(1)). That means a printer the phone can see: thermal printers with Bluetooth or Wi-Fi are common, and a web application prints through the system print dialog, so the printer has to be supported on the phone. Test printing before the first working day, on the paper you will use, because the QR code on paper must be between 40 and 50 mm. An electronic receipt may be sent to the buyer with their consent, but as we understand Article 13 of the rulebook, in addition to the printed one, not instead of it; only a seller who sells exclusively over the internet issues it instead of paper. Instead of a QR code an electronic receipt carries the verification address as a hyperlink.

What happens when the phone loses its connection

With a V-PFR, no connection means no signature, so no fiscal receipt. A good ESIR must not pretend at that moment that the receipt was issued. As we understand the law, a receipt has to be issued at the moment of the sale (Article 6(1)), and a receipt issued later, once the connection returns, is not. The law's answer to a dropped connection is a different one: whoever uses a V-PFR must also keep at least one working L-PFR in each business premises (Article 6(4)), unless they sell exclusively over the internet. In the meantime you hand the buyer nothing that looks like a fiscal receipt. That is why a V-PFR alone is not enough for a market stall or for a cafe; both also need an L-PFR on the premises.

Where a phone's limits are

• Private and business phone. A register on the phone that is also your private one means every cashier has access to your phone. For one person who sells alone, fine; for shifts of cashiers, a separate device is better.
• Battery and screen. A long shift and many items call for a charger and, realistically, a tablet. Neither is a legal condition, both are practical.
• The language of the receipt. The receipt is in Serbian, in Cyrillic or Latin script, regardless of the app's language; the journal the PFR returns is in Cyrillic. That is not a phone limitation but a rule for every register.
• Copies, refunds, advances. Every receipt and transaction type applies exactly as at the counter. An app that "does not have" refunds on a phone is not a smaller register but a deficient one.

Who a phone is the right register for

Field work and deliveries, a market stall, a small salon, services on call, the first months of a new shop before anyone knows how much turnover there will be. In all of those, the phone you already own and a printer the phone can see can be the register. As we understand the law, with a V-PFR every business premises, a vehicle or a stall included, also needs at least one L-PFR, and an electronic receipt can only go out in addition to the printed one. What is paid for at all in a register setup is broken down in How much a fiscal cash register costs.

What this looks like in Otkucaj

Otkucaj is a web application, so on a phone it runs in the browser and can be installed on the home screen (on Android from the browser menu, on iOS via Share and Add to Home Screen). Otkucaj on this site works with a V-PFR; the L-PFR that, as we understand the law, must also work in each business premises alongside it is obtained separately and must be approved by the Tax Administration. The register and the items are cached locally; a receipt caught by a dropped connection stays in a visible queue, clearly marked as not fiscalized, and it is not a fiscal receipt. Printing goes through the browser dialog; with the buyer's consent the receipt can also be e-mailed to them, with a verification link. All of it can be tried in the test environment before you request a security element for your own TIN.

Short version

• The law does not require a particular device but an approved ESIR, a PFR and a security element. A phone can be the register, but as we understand the law, with a V-PFR each business premises also needs at least one L-PFR, unless you sell exclusively over the internet.
• With a V-PFR the phone needs internet for every receipt; with an L-PFR on the premises, only the local network.
• The receipt goes to paper through a printer the phone can see; it can be sent electronically in addition, with the buyer's consent.
• Check the app in the Tax Administration register, then printing on real paper, before the first working day.