| PO Number | Town / Place name | Code
| | K01 | Felling |
|
| K02 | Hebburn |
|
| K03 | Walker |
|
| K04 | Helmshore |
|
| K05 | Stacksteads |
|
| K06 | Little Hereford |
|
| K07 | Shaw |
|
| K08 | Lymm |
|
| K09 | Woodborough, Wilts |
|
| K10 | Howden-le-Wear |
|
| K11 | Sinnington, Yorks |
|
| K12 | Earlestown |
|
| K13 | Brenchley |
|
| K14 | Liversedge |
|
| K15 | Ryton |
|
| K16 | Brotherton |
|
| K17 | Purston |
|
| K18 | Melplash |
|
| K19 | Carlton |
|
| K20 | Rawcliffe |
|
| K21 | Rawcliffe Bridge |
|
| K22 | Whitley Bridge |
|
| K23 | Ravenstonedale |
|
| K24 | Llanwnda |
|
| K25 | Plasmarl |
|
| K26 | Bexhill | |
| Bexhill-on-Sea |
|
| K27 | Bexhill Station |
|
| K28 | Fawley Station |
|
| K29 | Whitchurch |
|
| K30 | Goodrich |
|
| K31 | Goudhurst |
|
| K32 | Comshall |
|
| K33 | Coniston |
|
| K34 | Haswell |
|
| K35 | Murton | |
| Murton Colliery |
|
| K36 | South Hetton |
|
| K37 | Mumbles |
|
| K38 | Brayton Station |
|
| K39 | Dalston |
|
| K40 | Littlestone |
|
| K41 | Swinton |
|
| K42 | Northwood, Herts | |
| Northwood, Middx |
|
| K43 | Collingbourne Ducis |
|
| K44 | Mayfield |
|
| K45 | Saltford |
|
| K46 | Mangotsfield |
|
| K47 | Warmley |
|
| K48 | London and Holyhead T.P.O |
|
| K49 | Minster Ramsgate |
|
| K50 | Boot |
|
| K51 | Eskdale |
|
| K52 | Gosforth |
|
| K53 | Ravenglass |
|
| K54 | Arnside |
|
| K55 | Silverdale |
|
| K56 | Bigrigg |
|
| K57 | Bootle |
|
| K58 | Bootle Station |
|
| K59 | Silecroft |
|
| K60 | The Green |
|
| K61 | Kirkby-in-Furness |
|
| K62 | Furness Abbey |
|
| K63 | New Oxted |
|
| K64 | Lindal |
|
| K65 | |
|
| K66 | |
|
| K67 | Goring |
|
| K68 | Littleport |
|
| K69 | Wavnarllwyd |
|
| K70 | Shrewsbury and Nonmanton T.P.O. |
|
| K71 | Blockley |
|
| K72 | Lynmouth |
|
| K73 | Newbiggin Kirkby Stephen |
|
| K74 | Grimsby | |
| Peterborough Night Mail |
|
| K75 | Greenfield |
|
| K76 | Gwaun-cae-Gurwen |
|
| K77 | Cholsey |
|
| K78 | Witton Park |
|
| K79 | Lakeside |
|
| K80 | Calderbridge |
|
| K81 | Danby |
|
| K82 | Royton |
|
| K83 | Aynho |
|
| K84 | Heyford |
|
| K85 | King's Sutton |
|
| K86 | Somerton |
|
| K87 | Souldren |
|
| K88 | Hook Norton |
|
| K89 | Loddiswell |
|
| K90 | Haworth |
|
| K91 | Silsden |
|
| K92 | Pitsea |
|
| K93 | Waskerley |
|
| K94 | Clacton-on-Sea |
|
| K95 | Shipton-under-Wychwood |
|
| K96 | Hebden Bridge |
|
| K97 | Grimsby and Peterborough S.T. |
|
| K98 | Brighton and Hastings S.C. |
|
| K99 | Sheringham |
|
| L01 | London and Queensborough S.T. |
|
| L02 | Lincoln S.T. | |
| Lincoln S.C. |
|
| L03 | Rushden |
|
| L04 | Charlton-cum-Hardy |
|
| L05 | Norwich S.C. |
|