diff --git a/src/redis/subscribe.ts b/src/redis/subscribe.ts
index 8a7263d..97e0f20 100644
--- a/src/redis/subscribe.ts
+++ b/src/redis/subscribe.ts
@@ -36,10 +36,11 @@ export const redisSubscribe = async (deps: DependencyContainer): Promise<RedisCl
 
   const prefixWithTtl = redisPrefix !== undefined ? `${redisPrefix}:${TTL_PREFIX}` : TTL_PREFIX;
   await subscriber.subscribe(`__keyevent@0__:set`, async (message) => {
-    if (!message.startsWith(prefixWithTtl)) {
+    const isTtlKey = message.startsWith(TTL_PREFIX) || message.includes(`:${TTL_PREFIX}`);
+    if (!isTtlKey) {
       logger.info(`Redis: Got new request ${message}`);
 
-      const noPrefixMessage = redisPrefix !== undefined ? message.split(':')[1] : message;
+      const noPrefixMessage = redisPrefix !== undefined ? message.substring(`${redisPrefix}:`.length) : message;
       const ttlMessage = prefixWithTtl + noPrefixMessage;
       // eslint-disable-next-line @typescript-eslint/naming-convention
       await redisClient.set(ttlMessage, '', { EX: redisTTL });
diff --git a/tests/unit/redis/subscribe.spec.ts b/tests/unit/redis/subscribe.spec.ts
new file mode 100644
index 0000000..32710bb
--- /dev/null
+++ b/tests/unit/redis/subscribe.spec.ts
@@ -0,0 +1,165 @@
+/* eslint-disable @typescript-eslint/naming-convention */
+import jsLogger from '@map-colonies/js-logger';
+import { DependencyContainer } from 'tsyringe';
+import { Producer } from 'kafkajs';
+import { redisSubscribe } from '../../../src/redis/subscribe';
+import { REDIS_SUB, SERVICES } from '../../../src/common/constants';
+
+type SetCallback = (message: string) => Promise<void>;
+type ExpiredCallback = (message: string) => Promise<void>;
+
+const buildConfig = (prefix?: string): { get: jest.Mock; has: jest.Mock } => ({
+  get: jest.fn().mockImplementation((key: string) => {
+    if (key === 'redis.expiredResponseTtl') {
+      return 300;
+    }
+    if (key === 'redis.prefix') {
+      return prefix;
+    }
+    if (key === 'outputTopic') {
+      return 'test-topic';
+    }
+    return undefined;
+  }),
+  has: jest.fn().mockImplementation((key: string) => key === 'redis.prefix' && prefix !== undefined),
+});
+
+describe('redisSubscribe', () => {
+  let mockRedisClient: { get: jest.Mock; set: jest.Mock; del: jest.Mock };
+  let mockSubscriber: { subscribe: jest.Mock };
+  let mockProducer: { send: jest.Mock };
+  let setCallback: SetCallback;
+  let expiredCallback: ExpiredCallback;
+
+  beforeEach(() => {
+    mockRedisClient = {
+      get: jest.fn(),
+      set: jest.fn().mockResolvedValue(undefined),
+      del: jest.fn().mockResolvedValue(undefined),
+    };
+
+    mockSubscriber = {
+      subscribe: jest.fn().mockImplementation((channel: string, callback: SetCallback | ExpiredCallback) => {
+        if (channel.includes(':set')) {
+          setCallback = callback as SetCallback;
+        }
+        if (channel.includes(':expired')) {
+          expiredCallback = callback as ExpiredCallback;
+        }
+      }),
+    };
+
+    mockProducer = { send: jest.fn().mockResolvedValue(undefined) };
+  });
+
+  const setup = async (prefix?: string): Promise<void> => {
+    const mockContainer = {
+      resolve: jest.fn().mockImplementation((token: symbol) => {
+        if (token === SERVICES.REDIS) {
+          return mockRedisClient;
+        }
+        if (token === REDIS_SUB) {
+          return mockSubscriber;
+        }
+        if (token === SERVICES.CONFIG) {
+          return buildConfig(prefix);
+        }
+        if (token === SERVICES.KAFKA) {
+          return mockProducer as unknown as Producer;
+        }
+        if (token === SERVICES.LOGGER) {
+          return jsLogger({ enabled: false });
+        }
+        return undefined;
+      }),
+    } as unknown as DependencyContainer;
+
+    await redisSubscribe(mockContainer);
+  };
+
+  // ─── SET event: isTtlKey guard ────────────────────────────────────────────
+
+  describe('SET event — isTtlKey guard (no prefix)', () => {
+    beforeEach(async () => setup());
+
+    it('should NOT create a TTL key when message starts with "ttl:" (own sentinel)', async () => {
+      await setCallback('ttl:some-uuid');
+      expect(mockRedisClient.set).not.toHaveBeenCalled();
+    });
+
+    it('should NOT create a TTL key when message contains ":ttl:" (cross-instance sentinel)', async () => {
+      await setCallback('geo:ttl:some-uuid');
+      expect(mockRedisClient.set).not.toHaveBeenCalled();
+    });
+
+    it('should NOT create a TTL key for deeply nested TTL keys (the loop pattern)', async () => {
+      await setCallback('ttl:ttl:ttl:ttl:some-uuid');
+      expect(mockRedisClient.set).not.toHaveBeenCalled();
+    });
+
+    it('should create a TTL key for a normal UUID key', async () => {
+      await setCallback('abc123-def456');
+      expect(mockRedisClient.set).toHaveBeenCalledWith('ttl:abc123-def456', '', { EX: 300 });
+    });
+  });
+
+  describe('SET event — isTtlKey guard (with prefix)', () => {
+    beforeEach(async () => setup('geocoding'));
+
+    it('should NOT create a TTL key when message starts with "ttl:" (different instance, no prefix)', async () => {
+      await setCallback('ttl:some-uuid');
+      expect(mockRedisClient.set).not.toHaveBeenCalled();
+    });
+
+    it('should NOT create a TTL key when message contains own prefix sentinel', async () => {
+      await setCallback('geocoding:ttl:some-uuid');
+      expect(mockRedisClient.set).not.toHaveBeenCalled();
+    });
+
+    it('should NOT create a TTL key when message contains ":ttl:" from a different prefix (cross-instance)', async () => {
+      await setCallback('other_service:ttl:some-uuid');
+      expect(mockRedisClient.set).not.toHaveBeenCalled();
+    });
+
+    it('should create a TTL key for a prefixed original key', async () => {
+      await setCallback('geocoding:some-uuid');
+      expect(mockRedisClient.set).toHaveBeenCalledWith('geocoding:ttl:some-uuid', '', { EX: 300 });
+    });
+
+    it('should preserve the full key when stripping prefix — not truncate at second colon', async () => {
+      // old bug: split(':')[1] would give "part1" instead of "part1:part2:part3"
+      await setCallback('geocoding:part1:part2:part3');
+      expect(mockRedisClient.set).toHaveBeenCalledWith('geocoding:ttl:part1:part2:part3', '', { EX: 300 });
+    });
+  });
+
+  // ─── EXPIRED event handler ────────────────────────────────────────────────
+
+  describe('EXPIRED event handler', () => {
+    beforeEach(async () => setup());
+
+    it('should send no-chosen result to Kafka when wasUsed is false', async () => {
+      mockRedisClient.get.mockResolvedValue(JSON.stringify({ wasUsed: false }));
+      await expiredCallback('ttl:some-uuid');
+      expect(mockProducer.send).toHaveBeenCalled();
+    });
+
+    it('should NOT send to Kafka when wasUsed is true', async () => {
+      mockRedisClient.get.mockResolvedValue(JSON.stringify({ wasUsed: true }));
+      await expiredCallback('ttl:some-uuid');
+      expect(mockProducer.send).not.toHaveBeenCalled();
+    });
+
+    it('should always delete the original key after expiry', async () => {
+      mockRedisClient.get.mockResolvedValue(JSON.stringify({ wasUsed: true }));
+      await expiredCallback('ttl:some-uuid');
+      expect(mockRedisClient.del).toHaveBeenCalledWith('some-uuid');
+    });
+
+    it('should ignore expired keys that are not TTL sentinels', async () => {
+      await expiredCallback('regular-key');
+      expect(mockRedisClient.get).not.toHaveBeenCalled();
+      expect(mockRedisClient.del).not.toHaveBeenCalled();
+    });
+  });
+});