I'm not sure if it's still the same but in Devizes where I live you could send something 1st class which then went to Swindon for sorting, I have no problem with that. But, if you sent a letter 2nd class it would initially be sorted at the Devizes office. This meant that I actually once had a letter delivered the same day to a Devizes address as it was sent 2nd class. Strange but true as the recipient called me the same day to make sure I had dated it correctly.