Wow. The answer is most likely no, you do not. The permits are a huge thing - the client can claim that the work is no good because the permits were not secured. This is not necessarily the client's responsibility. As the contractor, you have to be sure that the work you are doing is LEGAL. As an unlicensed contractor, you will not be able to file a lien. Signing an estimate does not give you permission to do the work. You need to ALWAYS have a contract signed and dated stating the work to be done, the estimated price, and the client needs to also sign an agreement that any "overages" or changes to the original contractual plan will be charged and that he/she will pay the amended amounts if they are incurred. IF you had your contractor's license, you would already know these things. If you want to continue working as one, it would be prudent to consider getting one or perhaps getting a partner who already is licensed in the state of California. Presently, I can only suggest that you gather any receipts from the supplies that make up the retaining wall on the client's property and attempt to be reimbursed for the materials only. The client may be responsible to repay you for any out of pocket expenses, but, again, this is contingent upon the acknowledgement that the "estimate" is a form of a contract, which it may not be unless it clearly authorizes you and your crew to perform such work as outlined in the estimate. He can claim that he did not know that you were unlicensed nor was he made aware of the missing permits, which clears him from any liability to uphold his end of the casual bargain. By the way, your crew believed that they were working for you, and, therefore, you are liable for their wages regardless of whether the client pays you or not. Bummer.