Make a plugin work on specified domain only

You could use a combination of the file content and the domain to create a unique hash.

Example:

$md5 = md5( file_get_contents( __FILE__ ) . $_SERVER['HTTP_HOST'] );
if ( 'be5d38f32a5d4a897e6c878f0c2f1b14' !== $md5 )
    deactivate_plugins( plugin_basename( __FILE__ ) );

Additionally, you could check each week per remote request to your server, if the hash is registered for that domain.

But be aware, this can be changed very easily. There is just no way enforce a domain.

Related Posts:

  1. Open Source plugin and requires licence
  2. How to transfer a WordPress blog to a different domain?
  3. GPL and plugins
  4. Create plugin with 3rd party MIT license code
  5. Does releasing a plugin under the AGPL force people to open source their whole WordPress installation?
  6. Licensing: Can I include SWFs without source in a plugin released on wordpress.org?
  7. Licensing of freemium plugin
  8. Is license need for free wordpress plugin
  9. Best way to maintain and update 3rd-party WP plugin when developer is unresponsive?
  10. Multiple domains issue
  11. Can I put in Github the code of a abandoned plugin I want to fork?
  12. Can I use Symfony components in a plugin that I want to submit to the WordPress plugin repository?
  13. Custom license for WordPress plugin
  14. Is it fair to use MIT licensed code in WordPress plugins? [closed]
  15. Migrating WordPress – New domain entry, links broken
  16. Can i legally remove a credit from a free plugin on wordpress.org? [closed]
  17. Licensing options for WordPress Plugins
  18. How do I convert my WordPress website to be domain agnostic?
  19. Licensing a Plugin [closed]
  20. Single Domain/Multiple Domain installation restrictions allowed for plugins?
  21. How come W3TC is allowed to host premium code in the WordPress repo?
  22. best way to handle subscriptions with a licence?
  23. Team member plugin problem after changing to another hosting
  24. How set role at registration based on email?
  25. WordPress internationalization + domains
  26. Modify plugin and submit to directory
  27. Plugin with custom domain
  28. From a legal perspective, is it okay to customize a plugin’s code?
  29. How to Replicate Elementor Licensing Model
  30. to perform the requested action wordpress needs to access your web server. please enter your ftp
  31. How to edit a wordpress plugin without break its update process
  32. Rewriting every url
  33. Is there a good plugin for an online booking system..? [closed]
  34. Automating deprecated call checks?
  35. How can I make my custom shortcode work in a Custom HTML Widget?
  36. post_id always wrong in plugin
  37. Which hook callback has priority if both plugin and theme use the same hook?
  38. Adding a form at the end of the content
  39. Ajax call doesn’t work in frontend but it’s working in backend (when I’m logged in)
  40. Creating a wordpress plugin where users can override templates
  41. How to use static flattr buttons
  42. Allow Facebook to preview posts before published
  43. Can I run multiple queries with $wpdb->prepare?
  44. Get Plugin Information from Multiple Sites Externally
  45. javascript onload calling a function of a plugin
  46. Multisite Widget/Content
  47. May i Use ShortCode in Template?
  48. Best way to hook a custom url?
  49. plugin ajax to external php file always return null
  50. Best way to modify a plugin with no hooks and no pluggable functions?
  51. Auto delete WordPress users according to time
  52. Theme and plugin install or update display error in localhost
  53. Multiple sites, multiple countries
  54. Theme my Login plugin, how to update fields
  55. Is there a plugin-log plugin? [closed]
  56. Create a navbar filter that filters by a custom field
  57. Advanced Custom Field DatePicker [closed]
  58. Polylang : Interverting languages after development [closed]
  59. How to set Noindex to all wordpress pages in a catergory?
  60. Admin AJAX doesn’t work in plugin admin page – Even though code is copied verbatim from WordPress Codex
  61. WP_Query for custom post type and category_id not working
  62. Prevent plugin from intruding on wp-json posts api
  63. How do i get file_get_contents to work in wordpress
  64. Plugin Development – Functions or Hooks?
  65. What happens when WordPress memory limit is exceeded?
  66. Making that Admin Bar transparent or a blue color
  67. Use wp_upload_dir() correctly
  68. How can I automatically download all images from all imported posts, place them on my new host, and replace all the links
  69. Looking for a free quiz plugin which saves the candidates answers for review [closed]
  70. Allowing .rfa Files In Media Upload [duplicate]
  71. Some WordPress Posts are automatically becoming comments on other Posts
  72. What is the purpose of a companion plugin
  73. WordPress: Add custom add_filter for custom functions
  74. How to download and unpack / install plugins with templates when installing it
  75. Calling a class method instantiated by ajax call in wordpress [closed]
  76. Which Membership Plugins Allow Registered Users To Bookmark Posts? [closed]
  77. Per theme plugins?
  78. Calling PHP function with AJAX
  79. How to detect 404 url and make this link underline or change background color?
  80. Cron task gets removed from the schedule
  81. “Enable Media Replace” plugin does not update serialized object in WPMeta
  82. Failed to load resource: the server responded with a status of 500 () post.php
  83. How to show private pages based on a user’s role?
  84. admin-ajax.php not working properly on subdomains
  85. wp_login_form() ignoring login_form action hook
  86. My plugin can’t see my files
  87. wordpress disable certain plugins for catagory?
  88. Call to a member function get_error_messages() on null [closed]
  89. Menu items’ links are not working properly and added images
  90. getpost content with all formatting for admin pages
  91. WordPress ultra slow if I click on posts?
  92. Variable scope in plugin outside loop [closed]
  93. Pagination in category
  94. Can Shopp Commercial Plugin be hacked to display radio buttons instead of Dropdowns? [closed]
  95. wp_update_post does not change post status from draft to publish, returns 1
  96. No way to add instagram in AddToAny Plugin?
  97. Open all PDF or docx link as iframe
  98. Ajax in wordpress [duplicate]
  99. How to code a wordpress page properly? Dashboard or unique Theme files or alternative?
  100. Split Million WordPress Post’s Into Multiple Database Server