What a control unit does
The term control unit sounds technical, but the idea is simple: it is the part of the eTIMS setup that sits between your invoicing and KRA, registering each invoice and applying the control number and signature that make it a recorded tax document. When you see a control number and QR code on a compliant receipt, a control unit produced them.
For businesses integrating their own systems, KRA provides control unit types, the OSCU (Online Sales Control Unit) for online operation and the VSCU (Virtual Sales Control Unit), a software-based unit. Most businesses, though, never deal with a control unit directly: compliant software includes the control unit function, so it works behind the scenes and you simply issue invoices. Confirm the current control unit options and requirements with KRA if you are integrating.
Getting the basics right once means compliance runs quietly in the background of your business.
How the control unit fits your setup
A practical path for a Kenyan business.
- 1
Understand it is the KRA link
The control unit is what registers and signs your invoices with KRA. It is the reason a compliant invoice carries a control number.
- 2
Know your options if integrating
If you connect your own system, KRA provides the OSCU (online) and VSCU (software-based). Choose based on your setup and KRA's requirements.
- 3
Or let software handle it
Compliant software includes the control unit function, so you issue invoices and the registration and signing happen automatically.
- 4
Confirm requirements with KRA if needed
For a custom integration, confirm the current control unit options, setup and certification with KRA.
Common mistakes to avoid
Thinking you must manage a control unit yourself
Most businesses do not. Compliant software includes the control unit function, so it is handled behind the scenes.
Confusing OSCU and VSCU without assessing fit
If you do integrate, choose the control unit type that suits your connectivity and architecture, per KRA.
Ignoring the control number on receipts
The control number and signature show the invoice was registered. A receipt without them is not a recorded eTIMS invoice.
An owner demystifies the control unit
An owner in Mombasa kept reading about eTIMS control units and worried it was something complex she had to install and manage.
In practice, her compliant software included the control unit function, so every invoice was registered and signed with KRA automatically, and she never had to touch it.
Understanding that the control unit was the behind-the-scenes link to KRA, handled by her software, turned a confusing term into a non-issue.
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 makes this simple
Veira is built for Kenyan businesses. It issues compliant KRA eTIMS invoices automatically on every sale, applies the right tax treatment per item, captures the buyer KRA PIN, keeps your records reconciled and ready for filing, and reconciles M-Pesa and Pochi payments to each sale.
It runs on a free handheld terminal or the phone you already own, keeps working offline, and runs from KES 2,999 a month with a free terminal and a 30-day money-back guarantee. See how Veira works, or book a free demo.
Frequently asked questions
What is an eTIMS control unit?
What is the difference between OSCU and VSCU?
Do I need to install a control unit?
How do I know the control unit worked?
Does Veira handle this for me?
Where do I confirm the current rules?
eTIMS control unit is straightforward once you know the essentials, and with a compliant system like Veira the day-to-day part is handled for you. See how Veira works, or book a free demo. Always confirm current KRA rules and rates at kra.go.ke, as they can change.