Apple Pay Set Up Procedure

Apple Pay + NMI (SeamlessChex) — Merchant Integration Guide

Prerequisites

• Active NMI merchant account (under SeamlessChex).
• Apple Developer Program membership for the merchant’s Apple Developer account. 
• Apple Merchant ID (created in Apple Developer). 
• Apple Pay Payment Processing Certificate created using a CSR supplied by your gateway (NMI). The certificate is ECC 256 (prime256v1) and must be renewed about every 25 months. 
• For web only: ability to host a file at /.well-known/ on your domain.  
   

Step 1: Enable Apple Pay in NMI

1. Merchant Portal → Settings → Apple Pay
2. Enter Apple Merchant ID.
3. Generate CSR.
4. In Apple Developer, create Payment Processing Certificate using that CSR; download the .cer.
5. Upload the .cer back in NMI (note: renew ~every 25 months)
6. Web only — Domain verification
   1. Download the verification file from NMI Apple Pay settings.
   2. Host at: https://YOURDOMAIN/.well-known/apple-developer-merchantid-domain-association.
   3. Add your domain(s) in NMI Apple Pay settings.

Step 2: Integrate

A) Web (recommended) — Collect.js

1. Add Collect.js to checkout with your tokenization key and Apple Pay attributes.
2. On approval, Collect.js returns payment_token.
3. Server: POST to NMI Payment API (/api/transact.php) with your sale fields (e.g., amount) + payment_token. That’s it—no raw card data.

B) iOS App — PassKit

1. Enable Apple Pay capability, attach your Merchant ID.
2. Use PassKit to present the sheet and capture PKPaymentToken.paymentData.
3. Server: POST to NMI Payment API with your sale fields + Apple Pay token (no custom decryption). 

Step 3: Test → Go Live

• Use Apple Pay sandbox testers and run end-to-end.
• Confirm: certificate installed & valid, domain verified (web), transactions succeed via Payment API.

Common pitfalls (and fixes)

• “Apple Pay button doesn’t show on my site.”
  
  Verify the domain file is hosted at the exact /.well-known/ path and the domain is listed under Apple Pay in the NMI portal. 
   
• “Certificate errors” or sudden failures after a year or two.
  
  Payment Processing Certificates expire roughly every 25 months. Calendar a renewal 30 days in advance. 
   
• “Which key type for the certificate?”
  
  Use ECC 256 (prime256v1) for the Payment Processing Certificate. 
   
• “What do I actually post to NMI?”
   
  1. Web (Collect.js): post payment_token to the Payment API. 
      
  2. iOS app: post the Apple Pay token (paymentData) to the Payment API as enabled on your account; we’ll ensure the correct fields are turned on. 

Reference links (for developers)

• NMI — Digital Wallet (Apple Pay) Setup: domain verification, Collect.js attributes, and payment_token. 
   
• NMI — Payment API (Direct Post): endpoint and method. 
   
• NMI — Add Apple Pay to a Merchant (domains via API). 
   
• Apple — Configure Apple Pay (capability + Merchant ID + cert). 
   
• Apple — CSR and ECC details. 
   
• Apple — Setting up Apple Pay / PKPaymentToken. 
   
• Apple — Sandbox testing. 
   
• NMI — Apple Pay (Direct Connect) certificate lifecycle (useful for expiry planning; same cert rules apply).