How to fix failed high-value payments with Gravity Forms + Stripe: A WordPress case study

Why this matters

For organisations that rely on online donations or large payments, like charities, schools, or membership-driven services, failed transactions aren’t just annoying. They’re reputation-damaging and revenue-killing.

This post walks through a real-world case study where a high-profile charity was losing large donations (£1,000–£2,500) due to subtle but critical issues in their Gravity Forms + Stripe payment integration. If you’re using WordPress and taking payments or donations, this is what you need to get right, especially for high-value transactions.

The problem: Large donations were failing silently

Our client (a national charity) noticed something worrying:

• Donors were completing the donation process and approving payments in their banking apps…

• But Stripe never confirmed the transaction.

• No one was alerted – not the donor, not the charity’s team.

• The result? Thousands in lost donations and confused supporters.

This was happening primarily for donations above £1,000 – right when reliability matters most.

The underlying stack

• WordPress site

• Gravity Forms for donation forms

• Stripe Add-On for payments

• 3D Secure (Strong Customer Authentication) was in place

• Capture mode set to manual

7 Critical insights from our investigation

✅ 1. Manual capture mode creates extra risk

Using Stripe in manual capture mode means that even after a user authenticates payment, your server must send a second request to complete the transaction.

If anything fails (timeout, webhook issue, etc.), the donation stalls – even if the donor thinks it succeeded.

🔧 Fix: Switch to automatic capture for donations to reduce friction and risk.

✅ 2. Webhook failures break the flow

Stripe uses webhooks to finalise payments, especially after 3D Secure challenges.

If your server is down, overloaded, or blocked, Stripe can’t complete the transaction.

🔧 Fix:

• Monitor webhook health

• Ensure webhook URLs are always online and SSL-valid

• Add logging and alerts for failed webhook responses

✅ 3. No real-time donor feedback = confusion

Donors saw confirmation screens and approved payments in their banks…

…but the payment failed silently.

🔧 Fix:

• Use the payment_intent.payment_failed webhook to trigger:

  • A custom on-screen message

  • An automatic email to donor and admin

• Avoid generic success pages unless payment has been truly confirmed

✅ 4. 3D Secure flow is easily broken

3D Secure (SCA) adds extra steps. If the browser drops connection, times out, or fails to redirect, Stripe never gets final confirmation.

🔧 Fix:

• Test 3D Secure payments across devices, browsers and real-world scenarios

• Consider using Stripe’s hosted payment pages for better SCA handling

✅ 5. Your hosting affects payment reliability

We found failures clustered during specific periods – likely caused by temporary server issues (downtime, slow response times, SSL quirks).

🔧 Fix:

• Host your site on fast, reliable infrastructure

• Ensure uptime and performance monitoring is in place

✅ 6. Form plugins are not payment gateways

Gravity Forms is powerful – but it’s not Stripe. It relies on a lot of moving parts, and isn’t bulletproof for high-value payments.

🔧 Fix:

For high-value donations, consider:

• Stripe-hosted or embedded forms

• Dedicated donation platforms like Raiser’s Edge

• Routing donors to different flows based on donation amount (e.g. over £1,000 = redirected to a more robust hosted page)

✅ 7. Test high-value scenarios regularly

Most people test forms with £10 or £20. But high-value payments often behave differently due to SCA, fraud protection, and added security scrutiny.

🔧 Fix:

Create a staging environment and simulate:

• High-value donations

• Weak and strong internet connections

• Timeouts, browser closures, mobile banking approvals