I understand you to say: You were working as an independent contractor for an employer. While employed there, you worked for one of the employer's clients. Now, you are working for that client directly. You are worried that your former employer will not pay you for the work you did for it.
You had some kind of arrangement or contract with the employer, whether it was in writing or verbal. The contract probably required the employer to pay you for work you did. If so, the employer is still obligated to pay you for that work. If the employer does not, you can take it to Small Claims Court if the amount is up to $10,000 or to Superior Court if the amount is over $10,000.
Non-compete agreements are not valid in California, except in very rare circumstances which do no appear to exist in your situation. However, there may another kind of restriction that is relevant, even if you did not sign a document. Sometimes performing work is considered agreeing to certain terms.
Without knowing many more details, it is impossible to answer your question with any specificity. If the employer does not pay you, you will have to consult with one or more experienced employment law attorneys with whom you can discuss the details of your situation. You may want to review with the attorney whether you were really an independent contractor or if you should have been classified as an employee.
To find a plaintiffs employment attorney in California, please go to the web site of the California Employment Lawyers Association (CELA). CELA is the largest and most influential bar association in the state for attorneys who represent working people. The web site is www.cela.org. Click on "Find a CELA Member" and you can search by location and practice area. Many CELA attorneys represent clients throughout the state.
I hope you can resolve your situation and wish you the best.
twitter.com/MikaSpencer *** All legal actions have time limits, called statutes of limitation. If you miss the deadline for filing your claim, you will lose the opportunity to pursue your case. Please consult with an experienced employment attorney as soon as possible to better preserve your rights. *** Marilynn Mika Spencer provides information on Avvo as a service to the public, primarily when general information may be of assistance. Avvo is not an appropriate forum for an in-depth response or a detailed analysis. These comments are for information only and should not be considered legal advice. Legal advice must pertain to specific, detailed facts. No attorney-client relationship is created based on this information exchange. *** Marilynn Mika Spencer is licensed to practice law before all state and federal courts in California, and can appear before administrative agencies throughout the country. She is eligible to represent clients in other states on a pro hac vice basis. ***
Non-compete clauses in contracts are not upheld in California. If you were an independent contractor, you can sue or have an attorney write a demand letter to get the money owed to you. If you had a contract which states that your attorneys' fees must be paid by the company, then that will be upheld and if you prevail, they will be ordered to pay your attorneys' fees. If you were an employee and not an indep. contractor, you can also sue or have an attorney write a demand letter to try to get your wages plus one day's pay for each day you had to wait - up to 30 days PLUS your attorneys' fees. Call an employment law attorney to discuss.