This is Samuel and I will discuss this and provide you information in this regard.
Once the Petition for child support it filed, under CA Code
4009. An original order for child support may be made retroactive to the date of filing the petition, complaint, or other initial pleading. If the parent ordered to pay support was not served with the petition, complaint, or other initial pleading within 90 days after filing and the court finds that the parent was not intentionally evading service, the child support order shall be effective no earlier than the date of service.
A Judge determines that the parent and child are eligible to receive retroactive child support payments IF
1 - The non-custodial parent had concealed assets and finances to avoid paying child support payments or a lower amount
2 - The non-custodial parent acted in a way to delay the hearing and the payments were delayed as a result
3- The concludes that the payments must be backdated to a period that the non-custodial parent was not yet ordered to pay
Please let me know if you have other questions in this regard. Keep in mind, I can only answer and provide information for what you ask. I do not know what you need to know, unless you tell me. Please rate positive as this is how I get credit for my time and information.