Probate fees in California cannot be paid until the Court orders payment. This is usually at the end of the probate. I strongly advise you to seek the advice of another attorney. (Hopefully you have already done so because you indicate that this is your former attorney.) Do not pay this attorney anything without being ordered to do so by the Court.
DISCLAIMER: THE INFORMATION PRESENTED HERE IS GENERAL IN NATURE. IT IS NOT INTENDED, NOR SHOULD IT BE CONSTRUED, AS LEGAL ADVICE. THIS RESPONSE DOES NOT CREATE AN ATTORNEY-CLIENT RELATIONSHIP BETWEEN US. YOU SHOULD CONSULT WITH A QUALIFIED ATTORNEY FOR SPECIFIC LEGAL ADVICE ABOUT YOUR PARTICULAR SITUATION.
Your question is not clear. An "inheritance" loan is not necessarily a loan to the probate estate. If the estate is in probate, fees must be approved by the court before they are paid. Not so with trustee fees, unless the trust agreement unlikely provides otherwise, or with loans to beneficiaries who merely seek an advance of funds based upon their inheritance through a source other than the estate.
I am licensed in California only and my answers on Avvo assume California law. Answers provided by me are for general information only. They are not legal advice. Answers must not be relied upon. Legal advice must be based on the interplay between specific exact facts and the law. This forum does not allow for the discussion of that interplay. My answer to any specific question would likely be different if that interplay were explored during an attorney-client relationship. I provide legal advice during the course of an attorney-client relationship only. The exchange of information through this forum does not establish such a relationship. That relationship is established only by personal and direct consultation with me followed by the execution of a written attorney-client agreement signed by each of us. The communications on this website are not privileged or confidential and I assume no duty to anyone by my participation on Avvo or because I have answered or commented on a question. All legal proceedings involve deadlines and time limiting statutes. So that legal rights are not lost for failure to timely take appropriate action and because I do not provide legal advice in answer to any question, if you are an interested party you should promptly and personally consult with an attorney for legal advice. Also, see Avvo's terms and conditions of use, specifically item 9, incorporated by this reference
Based on your question, this sounds more like a personal loan to you as an advance on your inheritance. Probate Fees for attorneys are statutory. 4% first 100K, 3% next 100K, 2% on the next 800K and 1% thereafter. Fees are based on gross values. Filing fee is $435, and cost for probate referee is .1% of 1% of appraised value for real property and personal property other than cash.
If this is a probate, you should be very leery of the attorney. It does smell right.
The general advice above does not constitute an attorney-client relationship: you haven't hired me or my firm or given me confidential information by posting on this public forum, and my answer on this public forum does not constitute attorney-client advice. IRS Circular 230 Disclosure: In order to comply with requirements imposed by the Internal Revenue Service, we inform you that any U.S. tax advice contained in this communication (including any attachments) is not intended to be used, and cannot be used, for the purpose of (i) avoiding penalties under the Internal Revenue Code or (ii) promoting, marketing, or recommending to another party any transaction or matter addressed herein.