diff --git a/src/handlers/shared/start.ts b/src/handlers/shared/start.ts
index 8433e5b..c517d87 100644
--- a/src/handlers/shared/start.ts
+++ b/src/handlers/shared/start.ts
@@ -1,4 +1,5 @@
 import { Context, ISSUE_TYPE, Label } from "../../types";
+import { isUserCollaborator } from "../../utils/get-user-association";
 import { addAssignees, addCommentToIssue, getAssignedIssues, getAvailableOpenedPullRequests, getTimeValue, isParentIssue } from "../../utils/issue";
 import { HttpStatusCode, Result } from "../result-types";
 import { hasUserBeenUnassigned } from "./check-assignments";
@@ -82,7 +83,6 @@ export async function start(
     throw logger.error(error, { issueNumber: issue.number });
   }
 
-  // get labels
   const labels = issue.labels ?? [];
   const priceLabel = labels.find((label: Label) => label.name.startsWith("Price: "));
 
@@ -90,6 +90,19 @@ export async function start(
     throw logger.error("No price label is set to calculate the duration", { issueNumber: issue.number });
   }
 
+  // Checks if non-collaborators can be assigned to the issue
+  for (const label of labels) {
+    if (label.description?.includes("collaborator only")) {
+      for (const user of toAssign) {
+        if (!(await isUserCollaborator(context, user))) {
+          throw logger.error("Non-collaborators cannot be assigned to this issue", {
+            username: user,
+          });
+        }
+      }
+    }
+  }
+
   const deadline = getDeadline(labels);
   const toAssignIds = await fetchUserIds(context, toAssign);
 
diff --git a/src/utils/get-user-association.ts b/src/utils/get-user-association.ts
new file mode 100644
index 0000000..b626ef2
--- /dev/null
+++ b/src/utils/get-user-association.ts
@@ -0,0 +1,9 @@
+import { Context } from "../types";
+
+export async function isUserCollaborator(context: Context, username: string): Promise<boolean> {
+  const { data } = await context.octokit.rest.orgs.getMembershipForUser({
+    org: context.payload.repository.owner.login,
+    username,
+  });
+  return ["collaborator", "member", "admin"].includes(data.role);
+}