diff --git a/src/services/extensions/v2/developers-database.ts b/src/services/extensions/v2/developers-database.ts
index 0b82560..ef20188 100644
--- a/src/services/extensions/v2/developers-database.ts
+++ b/src/services/extensions/v2/developers-database.ts
@@ -1227,6 +1227,45 @@ export class DevelopersDatabase {
     }
   }
 
+  // Lets a claimant withdraw their own pending claim — scoped to
+  // claimant_id so this can't be used to cancel someone else's, and to
+  // status = 'pending' so a moderator's decision can't be undone by it.
+  async cancelClaim(
+    claimId: string,
+    claimantId: string
+  ): Promise<DatabaseResult<{ id: string }>> {
+    let result;
+    try {
+      result = await this.db
+        .prepare(
+          `DELETE FROM developer_claims WHERE id = ? AND claimant_id = ? AND status = 'pending'`
+        )
+        .bind(claimId, claimantId)
+        .run();
+    } catch (error) {
+      return databaseError("cancelClaim", error);
+    }
+
+    if (!result.success) {
+      return databaseError(
+        "cancelClaim",
+        new Error(result.error || "Database query failed")
+      );
+    }
+
+    if (!result.meta?.changes) {
+      return {
+        data: null,
+        error: {
+          message: `Cannot find pending claim by id: ${claimId}`,
+          code: "NOT_FOUND"
+        }
+      };
+    }
+
+    return { data: { id: claimId }, error: null };
+  }
+
   async listMyClaims(
     claimantId: string
   ): Promise<DatabaseResult<DeveloperClaim[]>> {
diff --git a/src/services/extensions/v2/index.ts b/src/services/extensions/v2/index.ts
index 029c315..26f7484 100644
--- a/src/services/extensions/v2/index.ts
+++ b/src/services/extensions/v2/index.ts
@@ -792,6 +792,67 @@ extensionsV2.openapi(claimDeveloperRoute, async (c) => {
   return c.json({ result: data }, 201);
 });
 
+const cancelClaimRoute = createRoute({
+  method: "post",
+  path: "/developers/claims/{id}/cancel",
+  tags: ["Developers"],
+  summary: "Withdraw the caller's own pending profile claim",
+  security: [{ Bearer: [] }],
+  middleware: [requireAuth()] as const,
+  request: { params: IdParamSchema },
+  responses: {
+    200: {
+      content: {
+        "application/json": {
+          schema: z.object({
+            result: z.object({ id: z.string(), cancelled: z.literal(true) })
+          })
+        }
+      },
+      description: "Claim withdrawn"
+    },
+    401: {
+      content: { "application/json": { schema: ErrorResponseSchema } },
+      description: "Missing or invalid bearer token"
+    },
+    404: {
+      content: { "application/json": { schema: ErrorResponseSchema } },
+      description: "No pending claim with that id owned by the caller"
+    },
+    422: {
+      content: { "application/json": { schema: ErrorResponseSchema } },
+      description: "id param failed validation"
+    },
+    500: {
+      content: { "application/json": { schema: ErrorResponseSchema } },
+      description: "Database error"
+    }
+  }
+});
+
+extensionsV2.openapi(cancelClaimRoute, async (c) => {
+  const auth = getAuth(c);
+  const { id } = c.req.valid("param");
+  const platform = getPlatform(c);
+  const db = new DevelopersDatabase(platform.getDatabase("DB_EXTENSIONS"));
+
+  const { data, error } = await db.cancelClaim(id, auth.userId);
+  if (error || !data) {
+    const status = error?.code === "NOT_FOUND" ? 404 : 500;
+    return c.json(
+      {
+        error: {
+          message: error?.message ?? "Unable to cancel claim",
+          code: error?.code ?? "DATABASE_ERROR"
+        }
+      },
+      status
+    );
+  }
+
+  return c.json({ result: { id: data.id, cancelled: true as const } }, 200);
+});
+
 const myClaimsRoute = createRoute({
   method: "get",
   path: "/developers/claims/mine",
diff --git a/test/services/extensions/v2/index.test.ts b/test/services/extensions/v2/index.test.ts
index e5fe183..b7653ff 100644
--- a/test/services/extensions/v2/index.test.ts
+++ b/test/services/extensions/v2/index.test.ts
@@ -2163,6 +2163,70 @@ describe("Extensions API v2", () => {
       );
       expect(reject.status).toBe(403);
     });
+
+    it("lets a claimant cancel their own pending claim", async () => {
+      seedUnownedDeveloper("legacy-developer");
+      const claim = await post(
+        "/extensions/v2/developers/legacy-developer/claim",
+        await authHeaders("user-1"),
+        {}
+      );
+      const claimId = ((await claim.json()) as { result: { id: string } })
+        .result.id;
+
+      const cancel = await post(
+        `/extensions/v2/developers/claims/${claimId}/cancel`,
+        await authHeaders("user-1")
+      );
+      expect(cancel.status).toBe(200);
+      const cancelled = (await cancel.json()) as {
+        result: { id: string; cancelled: boolean };
+      };
+      expect(cancelled.result).toEqual({ id: claimId, cancelled: true });
+      expect(tables.developer_claims.has(claimId)).toBe(false);
+    });
+
+    it("rejects cancelling a claim that belongs to someone else", async () => {
+      seedUnownedDeveloper("legacy-developer");
+      const claim = await post(
+        "/extensions/v2/developers/legacy-developer/claim",
+        await authHeaders("user-1"),
+        {}
+      );
+      const claimId = ((await claim.json()) as { result: { id: string } })
+        .result.id;
+
+      const cancel = await post(
+        `/extensions/v2/developers/claims/${claimId}/cancel`,
+        await authHeaders("user-2")
+      );
+      expect(cancel.status).toBe(404);
+      expect(tables.developer_claims.has(claimId)).toBe(true);
+    });
+
+    it("rejects cancelling a claim that is no longer pending", async () => {
+      seedUnownedDeveloper("legacy-developer");
+      tables.users.set("mod-1", { id: "mod-1", is_moderator: 1 });
+      const claim = await post(
+        "/extensions/v2/developers/legacy-developer/claim",
+        await authHeaders("user-1"),
+        {}
+      );
+      const claimId = ((await claim.json()) as { result: { id: string } })
+        .result.id;
+      await post(
+        `/extensions/v2/developers/claims/${claimId}/reject`,
+        await authHeaders("mod-1"),
+        { review_note: "no" }
+      );
+
+      const cancel = await post(
+        `/extensions/v2/developers/claims/${claimId}/cancel`,
+        await authHeaders("user-1")
+      );
+      expect(cancel.status).toBe(404);
+      expect(tables.developer_claims.get(claimId)?.status).toBe("rejected");
+    });
   });
 
   describe("GET /developers/{id}", () => {
@@ -2331,6 +2395,7 @@ describe("Extensions API v2", () => {
           "/developers/{id}/transfer/revoke",
           "/developers/transfers/accept",
           "/developers/{id}/claim",
+          "/developers/claims/{id}/cancel",
           "/developers/claims/mine",
           "/developers/claims",
           "/developers/claims/{id}/approve",
diff --git a/test/services/extensions/v2/mock-db.ts b/test/services/extensions/v2/mock-db.ts
index 790d999..4b7060c 100644
--- a/test/services/extensions/v2/mock-db.ts
+++ b/test/services/extensions/v2/mock-db.ts
@@ -1061,6 +1061,16 @@ class MockStatement implements D1PreparedStatement {
       return [];
     }
 
+    if (q.startsWith("DELETE FROM developer_claims WHERE id = ?")) {
+      const [id, claimant_id] = p;
+      const row = this.tables.developer_claims.get(String(id));
+      const eligible =
+        !!row && row.claimant_id === claimant_id && row.status === "pending";
+      if (eligible) this.tables.developer_claims.delete(String(id));
+      this.changes = eligible ? 1 : 0;
+      return [];
+    }
+
     if (q.startsWith("DELETE FROM developer_claims WHERE developer_id = ?")) {
       const [developer_id, owner_user_id] = p;
       let changes = 0;