The W (Western and Paddington) postcode area, also known as the London W postcode area is a group of postcode districts covering part of central and part of west London, England. The area originates from the Western (W1) and Paddington (W2-14) districts of the London postal district.
The Western district consists of the single original W1 postal district. The area it covers is of very high density development and it has been subdivided into a number of smaller postcode districts. Where districts are used for purposes other than the sorting of mail, such as use as a geographic reference and on street signs, the W1 subdivisions continue to be classed as one 'district'. In June 2000 there was a recoding of the area with the W1M, W1N, W1P, W1R, W1V, W1X and W1Y districts replaced.
Deliveries for W1 (and for WC1 and WC2) came from the Western District Office office on Rathbone Place, until it was decommissioned. This office was a stop on the former London Post Office Railway, which has been mothballed since 2003. The Western District Office was initially located on Wimpole Street, which was also a stop on the London Post Office Railway.
The Paddington district consists of thirteen postcode districts (W2–14). Apart from W2, the districts are arranged alphabetically, running from W3 (Acton) to W14 (West Kensington) and radiate westwards. The Paddington Head District Sorting Office was the western terminus of the London Post Office railway, which ran 6.5 miles (10.5 km) to the Eastern District Office at Whitechapel.