Sign in Get started

Home/Guides/Set up PayFast

Payments

How to set up PayFast for online payments

Let your customers pay invoices instantly via card or instant EFT. Here's every step from sign-up to your first live invoice.

1. Create a PayFast account

Go to payfast.io and click Sign up. You'll need your South African ID number or company registration number, a valid email address, and bank account details for payouts. PayFast is free to join — they charge a small percentage per transaction.

2. Find your Merchant ID and Merchant Key

Once logged in, go to Settings → Merchant Tools (or My Account on older dashboards). You'll see two values:

  • Merchant ID — a numeric string like 10000100. This uniquely identifies your PayFast account.
  • Merchant Key — a longer alphanumeric string. This authorises transactions on your behalf.

Copy both into MyFinance Studio under Settings → Payment methods → PayFast.

3. Set a passphrase (optional but recommended)

In PayFast, go to Settings → Security and create a passphrase. Enter the same passphrase in MyFinance Studio. This adds an extra layer of signature verification so that fraudulent notifications are rejected.

4. Understanding the Return URL field

The Return URL is where PayFast sends the customer back after a successful payment. In MyFinance Studio this field is optional:

  • Leave it blank (recommended) — MyFinance Studio automatically redirects the customer back to the invoice they just paid. No extra setup needed.
  • Set a custom URL — If you want customers to land on a specific "thank you" page on your own website, paste the full URL here (e.g. https://yoursite.co.za/thank-you).

In both cases, the actual payment is confirmed server-side via PayFast's ITN (Instant Transaction Notification), so the return URL only affects the customer's browser redirect — it does not affect whether the invoice gets marked as paid.

5. Sandbox vs live mode

Before going live, toggle Sandbox mode on in MyFinance Studio. This routes payments through PayFast's test environment so you can process test transactions with fake cards. Once everything works, turn sandbox off and your invoices accept real payments.

6. Test it end to end

  1. Enable sandbox mode in MyFinance Studio Settings.
  2. Open any unpaid invoice and click Pay online.
  3. Complete the PayFast checkout using their test card numbers.
  4. Confirm the invoice status updates to "Paid" automatically.

PayFast handles all card fraud detection and PCI compliance, so you never store card details. MyFinance Studio simply receives the confirmation and marks the invoice paid.

All guides Start free