You should provide your income information to RP regardless of whether your income has changed.
If RP’s calculations based on your updated income information show only a minor difference in child support (i.e. less than $10 per month or less than a 10% change in proportionate shares), RP will issue a Recalculation Decision stating that child support under the existing order is not changing. RP will not charge either parent a service fee in this situation.
See also: sample of a Recalculation Decision that doesn't change the child support payable - 36 KB .
Another option also is for you to provide your income disclosure directly to the other parent. If you both agree, you can then waive recalculation for that year.