title: How to create an iOS IPA file so that someone else can upload it to iOS Appstore?
body: <p>I'm building an app with someone else. They designed the graphics and I coded it. We're putting it in their app store account which means they did the certificate on their computer.</p>
  
  <p>Since I'm the coder, I've tried building the IPA file on my computer (using the certificate/password from them). It seems to build just fine, but when they try to upload it to iTunes, they get an ITMS-9000 error.</p>
  
  <p>I've built other IPA files and uploaded to my app store account without an issue. So, what am I missing on my side to properly build one with their credentials for their app store account?</p>