V-Look up

I was wondering if someone can help me. I’m trying to do what i feel should be a simple v-lookup but keep getting an error. So i have a series of data on one page- Zip codes to be exact. On another tab I have additional data: (Zip codes in column A and its correlating city in column B. I need to create a look up that matches the zips to the correct city on the first tab. Any help would be greatly appreciated.