Mac: Safari → Settings → Websites → Pop-up Windows → set the site to Allow. iPhone/iPad: Settings → Apps → Safari → turn off Block Pop-ups, then turn it back on afterwards.

The short explanation

On a Mac, Safari supports per-site pop-up rules, which is the safest option. iPhone and iPad only have a single on/off switch, so turn it off for the task and back on when you’re done.

Signs of the problem

  • A payment or login window doesn't open in Safari.
  • Safari shows a blocked pop-up notice.

Why it happens

  • Safari's default pop-up blocking.
  • Content blockers.

Fixes to try, in order

  1. Mac: per-site settingOpen the site, then Safari → Settings (Cmd+,) → Websites → Pop-up Windows → set the site to Allow.
  2. Mac: default for all sitesIn the same panel, set When visiting other websites to Allow (not recommended) or Block and Notify.
  3. iPhone/iPadSettings → Apps → Safari (older iOS: Settings → Safari) → turn off Block Pop-ups.
  4. Disable content blockers for the siteMac: Safari → Settings → Websites → Content Blockers. iPhone: tap aA in the address bar → Website Settings.
Check it's fixed: The pop-up opens when you retry the action.

Prevent it from coming back

Turn the blocker back on (iPhone) once you've finished.