Two names for the same job: signing an invoice so it counts as a tax invoice. The difference is what each one assumes about your connection at the moment of sale.
Both are software
Neither is a box you buy. KRA defines them as software modules that sit between your invoicing system and the Authority.
Both produce the same receipt
Signature, internal data, CU invoice number and QR code. A customer cannot tell which one signed their receipt.
Both are registered per PIN
A control unit belongs to a taxpayer PIN and a branch, with its own serial and its own invoice sequence.
Both sign before you print
A receipt is not valid until a control unit has signed it. That rule does not change between the two.
OSCU
Online Sales Control Unit
Each invoice is signed against KRA as it happens. It assumes a working connection at the moment of sale, and gives you the simplest possible model: one sale, one round trip, one signature.
Right for systems that are already online to do their job — cloud POS, e-commerce, an ERP your staff reach over the network.
VSCU
Virtual Sales Control Unit
Built for systems that cannot make that assumption: tills that must keep selling when the line drops, or volumes where a round trip per sale is the wrong shape.
Right for branch tills on unreliable connectivity, and for high-volume invoicing that batches rather than trickles.
Which one KRA expects of a particular taxpayer is a question for KRA or your tax agent, not for us. What we can tell you is what changes in your code, and the answer is close to nothing.
Your system POSTs an invoice and receives a signature. Which kind of control unit produced it is our side of the line, not yours — the request body, the webhook and the fiscal block are identical either way.
The reason the online-or-offline question usually gets asked is fear of the connection dropping mid-sale. That fear is already handled: an invoice we accept is queued, retried and reconciled, so a slow or unreachable KRA never blocks your till. You are notified when it is signed.
What actually happens when KRA is down →
Where we are today
VeTims is registered with KRA for both solution types, under one taxpayer PIN. OSCU is the path that runs today and the one every pilot uses. VSCU is registered and follows; if your tills need it, say so in your application and we will tell you where it stands rather than guess at a date.
Tell us how your tills connect and how much you invoice. We will say plainly which fits, and whether you need us at all.