More detail
Many small businesses assume eTIMS is a VAT-only rule. It is broader than that. The lighter eTIMS options exist precisely so small and non-VAT taxpayers can comply without heavy systems.
There is also a commercial reason. Your registered customers need an eTIMS invoice from you to claim their own expenses, so being unable to issue one can cost you their business.
Related questions
Is eTIMS Lite enough for a small business?
Veira gives Kenyan shops one calm app for selling, M-Pesa, KRA eTIMS and stock, with a free terminal. Book a demo and see it set up for your trade.