Remember, the (x, y) coordinates for the customers addresses are taken from the POSTCODE table.
In the postcode table, there are only 834 records.
London is huge and there are much more than just 834 postcodes in the city.
In addition, certain customers might live outside London, and their address is not captured in the POSTCODE table.
This is why some of the customers' (x, y) coordinates are missing.
In order to fix this, we will have to download the complete list of postcodes in the UK.
The data can be found here.
Scroll down and click on the ‘open_postcode_geo.csv.zip’ file:
For your convenience, we have already saved the file in the Data Files folder:
