These are;
First, Being a frequent Fuliza Loan User. I can't say for how long but as you keep been a regular user of Fuliza Loan Customer then you can be verified for a higher loan limit. This is because frequent usage will help you to develop a better Credit Score while also allowing the Lender to determine if you're Capable of repaying for a Loan.
Second and the Last step is, Continue depositing cash with your Mpesa Account. This is the main point you should take note on it. As long as you use your Mpesa Account for deposit cash the Fuliza Overdraft will immediately deducate from your Mpesa Account. This is done to determine the history of not receiving any Mpesa transaction or anything deposit in to your MPesa Account then the lender will probably ending up not giving you a chance to Qualify for Next level due to late repayment of your previous Loan taken.