overtime pay; overtime money
Refers to the extra money paid for working beyond regular hours. Common in workplace and legal contexts.
This month's overtime pay was higher than usual.
Some companies don't pay overtime.
手当 is a broader term for allowances or benefits, which can include overtime pay but also other types of extra payments.
fixed overtime pay; fixed overtime salary
Compound of 残業 (overtime work) and 代 (charge, fee).