Having a dress code

I am used to the dress code in the office since my employment has always been in the office with a dress code. But when I was assigned for a stint in London I was kind of surprised that the dress code is coat and tie. The suit is only worn by high ranking officers and a programmer like me would look out of place. But in London everyone wears a suit and tie. Would you believe that even a postman wears suit and tie?

Now I always have a coat and a tie just in case I have to wear it. For any occasion I feel prepared when I have those attire for formal occasions.