From Heathrow Terminal 1 train to Paddington (H&C Line)-Underground, Tube to London Kings Cross, then train to Kings Lynn. 2hrs 17min £50. From Heathrow Central Bus Station line 727 bus to Thetford, Bus Station then line 40 bus to King's Lynn, Bus Station. 5hrs 53min £30. From London Heathrow drive to King's Lynn. 2hrs 54min £23.