The TransitQuote booking form uses Google Maps Search to select addresses from a drop down list.

This is the same address search box that you will find on the Google Maps web page or app.

We use Google Directions to find out the distance and travel time between pick up and drop off addresses.

The Google Directions requires exact latitude and longitude coordinates on order to accurately work out the driving distance between two points.

Postal codes do not have coordinates because they refer to an area not an address.

Postcodes can also be duplicated between countries and Google also does not know about all possible postcodes in all countries the world.

For the above reasons postal codes can not reliably be used to enter addresses.

If Google decide to add postcode based address searches to their API we would consider adding this to TransitQuote, however at this time this does not appear to be something that is likely to happen.