Law Firm Crypto Retainer Checklist: What Bar Ethics Opinions Skip

TL;DR - Before your firm accepts a crypto retainer, screen the client's wallet for sanctions and stolen-funds exposure - bar ethics opinions cover fee reasonableness, not where the money's been.

Taking a Bitcoin retainer doesn't put your law license at risk. It can still put your trust account under a microscope. This checklist applies the moment a client offers a retainer in Bitcoin, Ether, or a stablecoin, before the transfer lands and while declining is still an option. It's written for solo and small-firm practitioners, not firms already running every wire through a KYT vendor.

Can a law firm legally accept crypto as a retainer?

Yes, in most US jurisdictions, as long as the fee stays reasonable and the client signs off in writing. DC Bar Ethics Opinion 378, issued in June 2020, held that a lawyer may accept cryptocurrency as payment provided the arrangement meets Rule 1.5's reasonableness standard. When the crypto functions as an advance on work not yet done, Rule 1.8(a) applies on top of that: the terms need written disclosure, the client needs a real chance to get independent advice, and the deal has to be fair to the client, not just convenient for the firm.

Rule 1.15 covers what happens after you accept it. Once you're holding a client's crypto, you're expected to safeguard it with the same competence you'd apply to a trust account. Perkins Coie has taken bitcoin retainers since 2013, and the ethics questions around it are largely settled by now.

None of that touches where the coins came from.

What do the ethics rules leave out?

The bar opinions that permit crypto retainers say nothing about screening the paying wallet for sanctions or stolen-funds exposure. They govern fee fairness and how you keep custody of funds once you have them, not the history behind the address that sent them. A firm that never checks the source can end up holding funds a regulator or opposing counsel later treats as tainted, regardless of whether the retainer amount itself was perfectly reasonable.

Plastron's own dataset carries more than 3,900 labeled Ethereum addresses, and 780 of them tie back to the OFAC sanctions list alone - a number that keeps climbing as Treasury adds new designations through the year. A firm that wants to check manually can pull up the paying address on Etherscan and scroll the transaction history for anything obviously wrong. That shows what moved, not what it means - spotting a mixer contract or a sanctioned counterparty by eye takes practice most managing partners haven't had reason to build. Instead of reading a raw transaction list, screen the wallet with Plastron and get one risk score covering sanctions, mixer, and stolen-funds exposure before you touch the retainer.

The checklist

Run these steps in order, before you accept the transfer or convert anything to fiat. Skipping ahead for a large or urgent retainer is exactly how the exposure gets missed.

1. Confirm your jurisdiction's bar has actually addressed crypto fees, and call the ethics hotline if it hasn't.
2. Put the fee arrangement in writing under Rule 1.8(a).
   • Spell out the valuation method, the conversion timeline, and who absorbs the loss if the price drops before you convert.
   • Give the client a real chance to get independent advice before they sign.
3. Get the exact paying wallet address in writing before the transfer, not after. A signed engagement letter or a dated email works; a screenshot pulled from a text thread doesn't.
4. Screen the address for sanctions, mixer, and stolen-funds exposure before you accept the transfer.
   • Run this while the coins are still in the client's wallet, while declining is still an option.
5. Refuse or return the payment if the address screens positive for a sanctions match.
   • A direct hit to the OFAC list isn't a business risk you negotiate around. Full stop.
6. Convert to fiat promptly once you've accepted the funds, and record the exchange rate at the time.
   • Most trust-accounting rules assume dollars, not a volatile asset sitting in a wallet for weeks.
7. File the screening result, the wallet address, and the transaction hash in the client's engagement record.
   • A bar auditor or malpractice carrier will ask for this before they ask about almost anything else in the file.

What happens if the wallet comes back flagged?

A flagged wallet doesn't mean the client lied to you. It means you stop before the funds move again. Hold the payment in the wallet that received it rather than forwarding it to your operating account or converting it right away.

Ask the client about the source of funds, and request a different payment method if the exposure looks material. Document the address and the conversation in the engagement file.

A distant, low-severity link usually just means tighter documentation going forward. A direct sanctions hit means returning the funds and declining the engagement, not explaining it away in a memo six months later. Your malpractice carrier will want a record either way.

FAQ

Can a law firm accept Bitcoin as a retainer under the Model Rules?

Yes. Most bar opinions that have addressed it, DC's among them, treat crypto like any other property payment, provided the fee is reasonable and the terms are disclosed in writing under Rule 1.8(a) when it's an advance on future work.

Does screening a client's wallet violate attorney-client privilege?

No. Wallet screening reads public blockchain data, not privileged communications. It tells you what an address touched before the payment arrived, nothing the client told you in confidence.

What if the wallet has a low-severity flag instead of a sanctions hit?

Document it and proceed with more scrutiny. Most flags sit well short of a sanctions match. Treat a distant link the way you'd treat an unusual wire from a new client: worth a question, not an automatic decline.

Do I still need to screen the wallet if the client is only paying an invoice after the work is done?

The ethics exposure is lower once fees are earned and billed in ordinary terms, but the source-of-funds exposure to your operating account doesn't disappear just because the invoice came first.

How often does the OFAC sanctions list actually change?

Often enough that an address that screened clean six months ago can be listed today. Treasury adds new designations through the year, and Plastron's corpus currently tracks 780 addresses tied to that list alone.