What a control unit does
Every compliant eTIMS invoice is signed by a control unit, which applies the digital signature and control number and transmits the invoice to KRA. Without it, an invoice is not compliant.
eTIMS offers more than one type of control unit so that a single phone till and a large integrated system can both comply. The two you will hear about are the OSCU and the VSCU.
How to choose between OSCU and VSCU
- 1
Consider your invoice volume
A virtual control unit often suits higher volumes and integrated systems; a device-tied online unit can suit simpler, single-point setups. Match the unit to how much you invoice.
- 2
Consider how you issue invoices
If you use an integrated POS or ERP, a VSCU usually fits the integration. A simpler standalone setup may use an OSCU.
- 3
Check your integrator or POS support
Your POS or integrator will usually recommend and set up the control unit that fits their solution. Confirm what they support.
- 4
Confirm with KRA
Requirements and the available options change. Confirm the current control unit options and any conditions with KRA before deciding.
OSCU vs VSCU at a glance
| OSCU | VSCU | |
|---|---|---|
| What it is | Online sales control unit, device-tied | Virtual sales control unit, software-based |
| Typical fit | Simpler or single-point setups | Integrated systems and higher volumes |
| Signs invoices for KRA | Yes | Yes |
| Produces a compliant invoice | Yes | Yes |
| Set up by | You or your integrator | Usually your integrator or POS |
Mistakes to avoid
Assuming one is more compliant than the other
Both produce compliant invoices. The difference is fit, not compliance.
Choosing without checking your POS
Your POS or integrator usually determines which control unit fits. Decide with them, not in isolation.
Ignoring volume
A unit that suits a low-volume till may not suit a high-volume integrated system. Match it to your invoicing.
Skipping KRA confirmation
Options change. Confirm the current choices with KRA rather than relying on old information.
A worked example
A growing business moved from a single phone till to an integrated POS across several branches and had to choose a control unit.
At a single till, a device-tied online control unit had been fine. With an integrated, multi-branch system and far more invoices, a virtual control unit fitted the integration better. Their integrator set it up, and invoicing scaled smoothly.
The right control unit followed the setup and volume. As the business grew, the answer changed.
Trading without eTIMS-compliant tax invoices risks KRA penalties, blocked VAT input claims for your customers, and receipts a business buyer cannot expense.
Veira signs every sale to KRA eTIMS automatically, so each receipt is compliant the moment it prints, with no separate device to reconcile.
How Veira helps
Veira sets up the right control unit for your business as part of onboarding, so you do not have to decide the technical detail yourself. Invoices sign and transmit correctly whether you run one till or several.
You get compliant invoicing without needing to understand the control unit mechanics. See how Veira works or book a demo.