How to set an interest rate on a child loan

Adding interest to a loan transforms it from a simple advance into a genuine financial lesson. Instead of just repaying what they borrowed, your child experiences the compounding reality that makes debt expensive — the same mechanics behind a bank loan in Nairobi or a mobile credit product. Before you set an interest rate, make sure you’ve already created the loan in KiddyCash; interest is configured as part of that loan’s settings and can’t be added to a disbursed loan retroactively.

When to use interest

Not every loan needs a rate. Interest works best when:

  • Your child is borrowing a meaningful amount relative to their allowance (e.g., KES 500–2,000)
  • You want them to weigh the true cost before agreeing to repay
  • You’re running a longer repayment period where the lesson needs weight over time

A small, same-week advance probably doesn’t need interest. A loan to buy a new phone or fund a side hustle? That’s exactly where a 5–15% rate sharpens the lesson.

Steps to set an interest rate

  1. Open the loan creation flow. Go to KiddyCash Loans and select New Loan. Choose the child from your family members list.

  2. Enter the principal amount and repayment schedule. Fill in the loan amount, start date, and how many instalments you want. These fields must be completed before the interest settings become active.

  3. Toggle on Interest. In the Loan Terms section, flip the Charge Interest toggle. The panel expands to show rate and calculation options.

  4. Set your rate. Enter a percentage in the Annual Interest Rate field. KiddyCash calculates monthly interest automatically based on this figure. For context, a 12% annual rate equals 1% per month — straightforward enough to explain to a 10-year-old.

  5. Choose simple or compound interest. This is the most consequential decision:

    • Simple interest applies the rate to the original principal only. Predictable, easier to explain.
    • Compound interest applies the rate to the outstanding balance each period. It grows faster and mirrors how real credit products (including many M-Pesa lending features) actually work.

    To understand how each option affects what your child ultimately repays, see how loan interest works as a lesson.

  6. Review the repayment breakdown. Once you’ve set the rate and interest type, KiddyCash shows a full repayment schedule — instalment by instalment — including the split between principal and interest. Walk through this with your child before you confirm. The moment they see that a KES 1,000 loan at 20% annual compound interest costs them KES 1,200 over a year, the lesson lands.

  7. Save and issue the loan. Tap Create Loan. The loan appears in your child’s wallet as a liability, and each scheduled deduction will show the interest component separately in their transaction history.

Adjusting the rate later

You can edit the interest rate on a loan that hasn’t been disbursed yet. Once the first repayment processes, the rate is locked. If you need to restructure, cancel the existing loan and create a new one with revised terms.

A note on keeping it fair

The goal is education, not punishment. A rate that’s punishingly high can breed resentment rather than financial awareness. Most parents in the KiddyCash community set rates between 5% and 15% annually — enough to make the cost real, not enough to make repayment feel hopeless.