diff --git a/README.md b/README.md
index a9d6b82..707a391 100644
--- a/README.md
+++ b/README.md
@@ -78,7 +78,7 @@ for (const item of items) {
     item.fields.priority,
     item.type === "REDACTED"
       ? "_redacted_"
-      : item.content.assignees.map(({ login }) => login).join(","),
+      : item.content.assignees.map(({ login }) => login).join(",")
   );
 }
 
@@ -484,7 +484,7 @@ Resolves with `undefined` if item cannot be found.
 ```js
 const item = await project.items.getByContentRepositoryAndNumber(
   repositoryName,
-  issueOrPullRequestNumber,
+  issueOrPullRequestNumber
 );
 ```
 
@@ -794,7 +794,7 @@ Archives a single item based on the Node ID of its linked issue or pull request.
 ```js
 await project.items.archiveByContentRepositoryAndNumber(
   repositoryName,
-  issueOrPullRequestNumber,
+  issueOrPullRequestNumber
 );
 ```
 
@@ -927,7 +927,7 @@ Removes a single item based on the Node ID of its linked issue or pull request.
 ```js
 await project.items.removeByContentRepositoryAndNumber(
   repositoryName,
-  issueOrPullRequestNumber,
+  issueOrPullRequestNumber
 );
 ```
 
@@ -1000,7 +1000,7 @@ try {
         details: error.details,
         // log out helpful human-readable error message, but beware that it likely contains user content
       },
-      error.toHumanMessage(),
+      error.toHumanMessage()
     );
   } else {
     // handle any other error
@@ -1032,7 +1032,36 @@ try {
         code: error.code,
         details: error.details,
       },
-      error.toHumanMessage(),
+      error.toHumanMessage()
+    );
+  }
+
+  throw error;
+}
+```
+
+#### `GitHubProjectNotFoundError`
+
+Thrown when a project cannot be found based on the `owner` and `number` passed to the `Project` constructor. The error is also thrown if the project exists but cannot be found based on authentication.
+
+```js
+import Project, { GitHubProjectNotFoundError } from "github-project";
+
+try {
+  await myScript(new Project(options));
+} catch (error) {
+  if (error instanceof GitHubProjectNotFoundError) {
+    analytics.track("GitHubProjectNotFoundError", {
+      owner: error.details.owner,
+      number: error.details.number,
+    });
+
+    myLogger.error(
+      {
+        code: error.code,
+        details: error.details,
+      },
+      error.toHumanMessage()
     );
   }
 
@@ -1062,7 +1091,7 @@ try {
       <td>
         <code>constant</code>
       </td>
-      <td><code>GitHubProjectUnknownFieldError</code></td>
+      <td><code>GitHubProjectNotFoundError</code></td>
     </tr>
     <tr>
       <th>
@@ -1156,7 +1185,7 @@ try {
         code: error.code,
         details: error.details,
       },
-      error.toHumanMessage(),
+      error.toHumanMessage()
     );
   }
 
@@ -1332,7 +1361,7 @@ try {
         code: error.code,
         details: error.details,
       },
-      error.toHumanMessage(),
+      error.toHumanMessage()
     );
   }