The other party's income has changed. Can child support be adjusted through a petition for adjustment of child support?

Hello. I am a family law attorney at Daeryun Law LLC.

If there is a change in the other party's income, it is possible to adjust the previously set child support again through a petition for adjustment of child support.

Under Article 837(5) of the Civil Act, the family court may, whenever it deems it necessary for the child's welfare, change matters concerning custody at any time.

That is, even for child support once set, if there is a change in circumstances, a claim for an increase or decrease can be made through a petition for adjustment.

A representative ground for adjustment is precisely an increase or decrease in the other party's income.

Where income has increased due to a promotion, a job change, or business expansion, the caregiving environment necessary for the child can also be provided more fully, so if it is determined that the existing child support does not match the current situation, a petition for adjustment of child support can be filed to seek an adjustment.

However, mere speculation or emotional assertions alone make it difficult for an adjustment to be accepted.

The court verifies whether there was an actual change in income through objective materials such as pay statements, income amount certificates, and health insurance premium payment records.

In addition, whether the change in income is temporary or continuous is also reviewed together.

In this process, if the assertions and the proof do not align, the adjustment may not be established, or it may instead lead to an unfavorable outcome.

Therefore, rather than blindly proceeding with the procedure merely on the ground that the other party's income has changed, it is important first to accurately determine whether the current situation is a matter that warrants filing a petition for adjustment of child support.

Daeryun, ranked 9th among law firms in Korea (based on 2025 National Tax Service value-added tax filings), provides thorough assistance from the drafting of a petition for adjustment of child support to the legal procedures.