| PO Number | Town / Place name | Code |
|---|---|---|
| 900 | Witham | |
| 901 | Pangbourne | |
| 902 | Witney | |
| 903 | Wiveliscombe | |
| 904 | Wokingham | |
| 905 | Wolverhampton | |
| 906 | Woburn | |
| 907 | Woodbridge | |
| 908 | Wembley | |
| 909 | Harrow Station | |
| 910 | Woodstock | |
| 911 | Elmham | |
| 912 | Deddington | |
| Hebron | ||
| 913 | Woodyates | |
| Crook Loc | ||
| Bexley Heath | ||
| 914 | Cranbourne | |
| Cranbourn | ||
| 915 | Wotton-under-Edge | |
| 916 | Furness Abbey | |
| 917 | Wickwar | |
| Askam | ||
| 918 | Worcester | |
| 919 | Llanfelteg | |
| 920 | Upton-on-Severn | |
| 921 | Workington | |
| 922 | Worksop | |
| 923 | Worthing | |
| Worthing Station Office | ||
| Worthing Station B.O. Worthing | ||
| Montague St. Worthing | ||
| 924 | Wrexham | |
| 925 | Wymondham | |
| 926 | Yarm | |
| 927 | Yarmouth | |
| Great Yarmouth | ||
| 928 | Yealmpton | |
| Crowboro' Cross | ||
| 929 | Yeovil | |
| 930 | York (C) | |
| Michelgate, York | ||
| Strensall Camp, York | ||
| 931 | Easingwold | |
| 932 | Escrick | |
| Barnetby | ||
| 933 | Hamerton | |
| Hillsborough | ||
| 934 | Helmsley | |
| Mundford | ||
| 935 | Kirkby Moorside | |
| Castle Acre | ||
| 936 | Whitwell | |
| 937 | Barnet | |
| 938 | Croydon | |
| Croydon E. | ||
| Croydon S. | ||
| Croydon W. | ||
| New Thornton Heath Croydon | ||
| Thornton Heath | ||
| Thornton Heath High St | ||
| 939 | Staplehurst | |
| 940 | Alne | |
| Litcham | ||
| 941 | Burton Agnes | |
| Three Cocks | ||
| 942 | Bradbury | |
| Larnaca | ||
| 943 | Beaminster | |
| 944 | Lynton | |
| 945 | Runcorn | |
| 946 | Middlesboro' | |
| 947 | Hartlepool | |
| 948 | Bruton | |
| 949 | Castle Cary | |
| 950 | Kenilworth | |
| 951 | Pontypool | |
| 952 | Hollytroyds | |
| Greenhithe | ||
| 953 | Blackpool | |
| South Shore Blackpool | ||
| 954 | Longtown | |
| 955 | Otterton | |
| Southboro' | ||
| 956 | Hurstpierpoint | |
| 957 | Nuneaton | |
| 958 | Leigh | |
| Fencehouses | ||
| 959 | Clifton | |
| Long Sutton | ||
| 960 | Crewe | |
| 961 | Sutton Bridge | |
| 962 | Middleham | |
| 963 | Winchfield | |
| 964 | Euston Square Station | |
| 965 | Alderney | |
| 966 | Hadlow | |
| 967 | Edenbridge | |
| 968 | Winchelsea | |
| 969 | Nicosia | |
| 970 | Washford | |
| 971 | Ventnor | |
| 972 | Flint | |
| 973 | Rhyl | |
| 974 | Sedburgh | |
| Kyrenia | ||
| 975 | Easingwold | |
| Limassol | ||
| 976 | Windermere | |
| 977 | Ferry Hill | |
| 978 | Littlehampton | |
| 979 | Acklington | |
| 980 | Rhymney | |
| 981 | Paphos | |
| 982 | Dowlais | |
| Famagusta | ||
| 983 | Soham | |
| 984 | Mere | |
| 985 | Aberdare | |
| 986 | Treherbert | |
| 987 | Burbage | |
| Treorchy | ||
| 988 | Ystrad Rhonnda | |
| 989 | Ton-y-Pandy | |
| 990 | Collingbourn | |
| Dinas | ||
| 991 | Porth, Glam | |
| 992 | Tidworth | |
| Pen-y-graig | ||
| 993 | Chalderton | |
| Ferndale | ||
| Blaenllecha | ||
| 994 | Axbridge | |
| Treallaw | ||
| 995 | Brierley Hill | |
| 996 | Sturminster | |
| 997 | Shillingstone | |
| Pinxton | ||
| 998 | Charfield | |
| 999 | Paulton |