WhatsApp is where many Tanzanian customers prefer to talk, and that is a good thing. The trouble starts when the chat history becomes your only record of who asked what, who was quoted and who needs a call back.
Name your stages
You do not need software to begin. Agree on four or five stages that describe how a customer moves from first message to payment, for example: new enquiry, quote sent, negotiating, won, lost. Everyone on the team should use the same words.
Give every lead an owner and a next step
A lead without a named person and a next action is a lead that will go cold. This one habit does more for conversion than any tool.
Then add the tool
Once the process works on a shared sheet, move it into a CRM so that reminders, reports and customer history happen automatically. Keep talking on WhatsApp. Just stop relying on it as your filing cabinet.