Rates are quoted per annum
Every rate on Kipit is quoted per annum (p.a.). A 90-day plan at 18% p.a. does not pay 18% of your money — it pays roughly a quarter of that, because you only hold it for a quarter of a year.
The quick maths: principal × rate × (days ÷ 365). ₦500,000 at 18% p.a. for 90 days earns about ₦22,192 before tax.
Why longer tenors pay more
You are being paid for two things: lending your money, and giving up access to it. The longer you lock funds, the more certainty the issuer has, so the rate rises with tenor.
That extra rate is only worth it if you genuinely will not need the money. Breaking a fixed plan early usually costs part of the accrued interest.
Effective yield and compounding
Effective yield is what you actually earn once reinvestment is included. Rolling a 90-day plan four times at 18% p.a. earns slightly more than one 365-day plan at 18% p.a., because each rollover reinvests the interest.
The trade-off is rate risk: your rollover happens at whatever rate is available then, while a one-year plan locks today's rate for the full period.
A simple rule
Keep money you may need within 30 days in the Call Account, where interest accrues daily and you can withdraw anytime. Lock the rest into the longest tenor you are genuinely comfortable with.