The short answer
both are an integration between your own software and eTIMS, and they differ in the invoicing rhythm they assume. The choice follows from how your business issues invoices: how many, how fast, and whether the connection holds while you do it.
Side by side
| OSCU (Online Sales Control Unit) | VSCU (Virtual Sales Control Unit) | |
|---|---|---|
| Kind of thing | A control unit specification that integrating software is written against, not something a business installs by itself. | A control unit specification that integrating software is written against, distinguished from the online unit by how it handles volume and connection. |
| Runs on | a server, Windows | a server, Windows |
| Connection | Needs the connection up | Copes with drops |
| Invoice rhythm | Each invoice, live | Volume, handled in bulk |
OSCU (Online Sales Control Unit)
One of the two control units a system-to-system integration is built against. The online variant, which works with the connection up. Invoices as they happen, with the connection carrying each one.
VSCU (Virtual Sales Control Unit)
The other control unit a system-to-system integration is built against. The virtual variant, which is the one that comes up where invoices are handled in bulk. Volume. The virtual unit is the answer when invoices arrive faster than a live round trip per invoice makes sense.
How to choose between them
Our reading, not a rule. Nothing below is a statement of what KRA requires.
OSCU (Online Sales Control Unit) gets awkward when
Trading conditions where the connection genuinely drops, which is the problem the virtual unit addresses.
VSCU (Virtual Sales Control Unit) gets awkward when
A small business, for whom none of this is a decision they need to make.
What the rules say
Stated by the publisher from the cited KRA material. Our reviewer has not yet re-checked it against the source, so confirm anything you are about to act on with KRA directly.
KRA identifies several categories of eTIMS solution, among them eTIMS Online, the eTIMS Client, eTIMS Lite, system-to-system integration, reverse invoicing and buyer-initiated invoicing. Which one suits a business depends on how it issues invoices rather than on what it sells.
Tax rules in Kenya change with each Finance Act and with regulations made during the year. Before acting on any figure, deadline or threshold, check the current position on KRA's own website.
This page explains how a requirement generally works. It is not tax advice, and it cannot account for the specifics of any one business. For a position you intend to rely on, confirm with KRA directly or with a registered tax agent.
Common questions
Which is better, OSCU (Online Sales Control Unit) or VSCU (Virtual Sales Control Unit)?
Neither, as a general matter. They assume different invoicing patterns, and the one that suits a business follows from how many invoices it issues and how reliable its connection is.
When would OSCU (Online Sales Control Unit) be the wrong choice?
Trading conditions where the connection genuinely drops, which is the problem the virtual unit addresses.
How do I know this information is current?
Tax rules in Kenya change with each Finance Act and with regulations made during the year. Before acting on any figure, deadline or threshold, check the current position on KRA's own website.
Sources
- officialeTIMS (Electronic Tax Invoice Management System) — Kenya Revenue Authority, checked 2026-09-18
- officialKenya Revenue Authority — Kenya Revenue Authority, checked 2026-09-18