procedure for transferring physicial primary custody of child to husband under CA child custody laws

Since he is almost 18, he is capable of choosing where he wants to live and the courts should not be involved in making decisions when you are all in agreement.

I agree that since your son is 17, a court would in most cases permit him to decide with which parent he wishes to reside. If you and his father are in agreement, you may transfer custody without involvement of the court. However, such an agreement should be filed with the court together with a complaint for modification (or other similar pleading in Texas) if his father was ordered to pay child support in a prior Judgment. In that case, a transfer in physical custody will generally result in a termination of his child support obligation and so the best course of action would be to inform the court of the change in circumstances - the transfer in custody - and formally terminate the child support obligation.

Bearing in mind that the ultimate answer to a question like this will depend upon where the court orders come from (Texas, California, or wherever) them, my thoughts are as follows: generally speaking, a 17-year-old child will be given a lot of leeway and deference by the court in its attempt to respect the desires of the child regarding where he wants to live. This is not to say, however, that it is unheard of for the courts to become involved in this type of question; however, generally speaking, they will defer to the child's wishes. As you point out, the more important question is whether or not this change in physical custody needs to be documented with the court. Practically speaking, every aspect of the otherwise "court supervised" custody and visitation of a minor child (even one who is 17) should be documented at the court, If for no other reason than for the accuracy of the record. However, there are other reasons why this is advisable. I assume that the child's father is paying you child support. It will make his life a lot easier if the two of you enter into a written agreement regarding a change in physical custody and, at the same time, acknowledging that he will no longer pay you support. Have the two of you discussed whether you will now pay him support? This is something else that can (and should) be discussed between the two of you and included in the court documents. Doing so will prevent either you or your ex husband from chasing the other later for monies that are felt "should be” or “should have been” paid. As always, it is best to consult with an experienced family law attorney in these situations, and I encourage you to do so. The type of modification document that you would require should be very simple and easy to prepare and should not cost a lot of money.