The phrase "an additional job" is correct and usable in written English.
You can use it when referring to a job that is added to an existing workload or responsibilities.
Example: "After taking on an additional job, I found it challenging to balance my time effectively."
Alternatives: "an extra job" or "a supplementary job".
I got an additional job writing ad copy for Amazon.
"Every 22 additional Chinese visitors we attract supports an additional job in tourism.
Workers who fall below this threshold must increase their work with their current employer, or look for an additional job or for a new one.
While reviewing films for the BBC, he took on an additional job with NBC, broadcasting a weekly "London Letter" back to the United States.
But during the off-season, Mr. Thomas -- a Hall of Fame point guard who played for the Detroit Pistons -- said he couldn't resist juggling an additional job: popcorn franchise owner.
Mr. Hawkins, the museum's former executive vice president and counsel to the trustees, has recently taken on an additional job as a special consultant to Christie's, trying to raise its profile in the United States.
The $17.4 billion in loans represents a necessary bridge over the road to liquidation, protecting the economy from a wave of additional job losses.
That amounts to an immediate loss of roughly 600,000 jobs (at current employment levels) and a similar-sized additional job loss every year in the future.
Associate professional careers, encompassing roles as diverse as financial advisers and dental technicians, will expand by a quarter of a million additional jobs.
Graduate study allows for further specialization in a particular field and additional job and advancement opportunities.
Suppliers are the largest manufacturing employer in seven states and are the nation's largest manufacturing sector, with each supplier job contributing an additional five jobs to the United States economy.
