Besides taking number 1, can driver change his current number and take another one between the seasons? For example, can Hamilton change his number 44 to let’s say 99 (Sutil’s old number?)? I know that they can’t take numbers that aren’t currently used, but are used in the past two seasons, like which would be Alonso’s 14.
I asume that they can’t change numbers during the season.
The exception would be if a driver left F1, stayed out for two full seasons (thus losing their right to their original number) and then rejoined F1. At that point, they could either retake their old number (assuming nobody else has reserved it) or pick a different one.
That’s the theory but it hasn’t happened in practice. Will Steven’s ran number 28 in 2015, so in theory the number should not have been available in 2016 and 2017. However Brendon Hartley selected that number at the end of the 2017 season as his permanent race number.