How to Find Amazon Pay Prohibited Business Categories and Products

How to use Google's `intext:` and `site:` operators to surface products that fall under Amazon Pay's prohibited categories.

[Android] How to Test In-App Purchases in Debug Build

Sign the debug APK with the release key and use Google Play alpha or beta tracks to test in-app purchases.

List of Items Obtainable from Apple Pay Billing Address

Which fields Apple Pay's billing address exposes in Japan — spoiler: no phone number.

When Basecamp Payment is Overdue, You Obviously Can't Use It at All...

If a Basecamp renewal payment fails, the account gets frozen and becomes completely unusable.

Pros and Cons of Using Bitcoin for Online Payments Based on My Experience

Pros and cons I noticed paying online with Bitcoin instead of a credit card in Portland.

Difference Between China's Country Codes CN and C2 #country_code

The difference between PayPal's CN and C2 country codes for China, and how to use each in cross-border e-commerce.

Experience Report: Completely Cashless, Walk-through Store 'Developers.IO CAFE'

Visiting Classmethod's fully cashless, walk-through Developers.IO CAFE as implementation reference.

PayPal Does Not Have a Function to Block Specific Accounts

PayPal has no built-in account block list, so I note how to implement one on the merchant side with SetExpressCheckout and GetTransactionDetails APIs.

PayPal RefundTransaction API cannot refund after 180 days from payment date

The PayPal RefundTransaction API cannot refund after 180 days — notes on workarounds with MassPay and DoNonReferencedCredit APIs.

[PayPal] TOKEN Valid Time is 3 Hours by Default, Maximum 72 Hours

The PayPal SetExpressCheckout TOKEN is valid for 3 hours by default and up to 72 hours on request.

[PayPal] Transaction cannot complete. error cause is unknown even to PayPal employees, so you have to contact credit card companies or banks

PayPal API Error 10417 Transaction cannot complete. — even PayPal cannot pinpoint the cause, so customers must contact their card issuer or bank.

Shopify Cart Addition and Checkout Inventory Allocation Verification Results

Concurrent checkouts across Shopify Payments and Amazon Pay can drive inventory negative — verified.

Setting Smaregi 'Credit Manual Input' Function to OFF

Two ways to turn off Smaregi's Credit Manual Input feature — from the management screen or per app.

Stripe Local Fukuoka - The Reality of B2B Payments in Japan and the Evolution of Stripe

I attended Stripe Local Fukuoka and learned about the latest trends in payment processing and B2B transactions. Stripe can process single payments up to 99,999,999 JPY, and B2B credit card transactions in the range of 10,000 to 99,999,999 JPY are more common than you might think. I also shared my experience of building Tax, Subscription, and Radar features from scratch before Stripe offered them natively.

Payment Service Comparison for Global SaaS Launch - Stripe Payments or Zuora Billing

For payment services for global SaaS, I recommend starting with Stripe Payments due to its cost-effectiveness and ease of implementation.

[Stripe] About Refund Cancellation/Reversal Processing

Stripe refunds can't be cancelled — the workaround is to re-charge via Create Payment in the Stripe dashboard.