Building a WhatsApp-First Fintech Product: Lessons from TrothFin

Why WhatsApp as the main interface

TrothFin is an earned wage access service for Nigerian workforces. It lets employees draw part of the salary they have already earned before payday, with the employer coordinating the arrangement. When we designed it, the first question was where the users already are. Frontline workers do not want another app to download, register for and remember. They already use WhatsApp every day. So we made WhatsApp the main interface and built a web dashboard only for the people who manage the service, such as administrators and company accountants.

How a chat interface differs from a normal app

A web app gives you buttons, forms and screens. A chat gives you free text. That changes the design in several ways:

• Commands have to be simple and forgiving. We route messages by command and handle small variations in spelling and case.
• Every reply must tell the user what to do next, because there is no menu to fall back on.
• State is invisible, so the system must remember where each person is in a multi-step flow, such as onboarding, and resume cleanly if they come back later.
• Identity comes from the phone number. That is convenient but also makes careful verification essential.

Onboarding that builds trust

Money products live or die on trust, so onboarding is not a formality. A new employee goes through a sequence of confirming a one-time code, choosing a personal PIN, adding bank details and verifying employment. We treat each step as a gate, and we keep the messages short and reassuring. The goal is that a first-time user understands what is happening and feels safe at every step.

Pricing and rules belong in code you can test

Fees, caps and rebates are business rules, and business rules change. We isolated them in a dedicated pricing component rather than scattering them through message handlers. That makes the rules easy to read, easy to test with automated tests and safe to change, which matters when real money is involved.

Payments need a reliable gateway integration

Moving money means integrating with a payment gateway properly. We use Paystack and design for the unhappy paths: pending transactions, failures, duplicate notifications and reconciliation. Every payout is recorded with its fee, net amount and any employer share, so the ledger can always be audited.

Two audiences, two interfaces

The employee experience is a chat. The control experience is a server-rendered web dashboard with separate areas for the platform administrator and for each employer. Administrators can activate or deactivate a company and monitor risk. Employers upload their payroll roster and download deductions for the month. Keeping these interfaces separate keeps each of them simple.

What we would tell other teams

• Pick the channel your users already live in, and design for it instead of copying a web layout.
• Treat identity and verification as the core of the product, not an add-on.
• Put pricing and limits in isolated, well-tested code.
• Build the admin tools early, because operations teams need them from day one.
• Log every financial event so you can reconstruct what happened later.

Talk to us

If you are planning a messaging-based product, a fintech workflow or an integration with the WhatsApp Cloud API, we would be glad to help. See TrothFin in our portfolio, or get in touch.