"It might seem like a little thing, but it's an important distinction. Phillip will forever remain 63 not out," said CA chief James Sutherland.
Hughes was hit by a bouncer from Sean Abbot during a domestic match earlier in the week. He was to turn 26 today.
Australian captain Michael Clarke took to Twitter to share his feelings on the death of his "little brother", a day after paying a moving tribute to the left-handed batsman.
Australia one-day opener Aaron Finch too wished his former teammate.
"Happy birthday brother! With us forever!! Just a standard day, walking around the house in your baggy green! Haha," he wrote.
Fast bowler Peter Siddle said: "I'm going to miss your cheeky smile, but I'll never forget it".