More detail
A compliant invoice is more than a list of items and a total. It carries identifying and control information that lets KRA and a customer verify it.
The reassurance for a shop is that you do not memorise the required fields. A system that issues eTIMS invoices includes them automatically, which is much of the value of using one.
Related questions
Does the receipt need a QR code?
Do I add the tax details myself?
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.