A breach starts two kinds of obligations, duties to clients under ABA Opinion 483 and Texas notice deadlines, and here is what each asks and what to settle in advance.
An odd login alert, a call from a vendor, an email account sending messages nobody wrote. Within the hour you are asking what happened, whose information is involved, who must be told and by when. Those are the right questions, and the answers sit in more than one place.
What lawyers owe clients
ABA Formal Opinion 483 (October 17, 2018) says, as the ABA describes it, that lawyers must monitor for breaches, stop a breach and restore systems, determine what happened (the scope of the breach), and notify current clients with enough detail to keep them informed and support their decisions. The list begins before the breach, and for good reason: a firm that cannot see its own systems will struggle to scope an incident, and you cannot tell a client what you have not scoped.
The Texas clocks
Under Texas Business and Commerce Code Sec. 521.053, you notify affected individuals without unreasonable delay and not later than the 60th day after the date you determine a breach occurred, with exceptions such as a law enforcement delay. If the breach involves at least 250 Texas residents, you also notify the Texas Attorney General not later than the 30th day after determining the breach occurred, electronically through the Attorney General's form.
Both clocks run from the date you determine the breach, so that date matters, and the Attorney General's deadline is the shorter one. I am reading these as an auditor and not as your lawyer, so this is not legal advice.
How common it is
In the ABA's 2023 survey, a national survey, 29% of respondents said their firm had experienced a security breach, up from 27% the prior year. Another 52% said no, and 19% did not know, which tells me that simply being able to see what happens on your systems is part of the work.
What I would do first
First, I would name who may determine that a breach has occurred, with a backup, and have that person record the date and time at once. Second, I would make sure you know where client information lives, who can reach it and what logs exist, so you can actually scope an incident. Third, I would keep a printed contact sheet with your attorney, your IT provider, your insurer if you have one, and whoever speaks to clients, with a copy kept somewhere other than the systems that might be down. Software helps with monitoring and restoring, but the people on that sheet make the decisions. Finally, I would draft a plain client notice now, with blanks for what happened, what information is involved and what the firm is doing, so you are filling in facts instead of composing under pressure.
If you would like to build this plan before you need it, a call with AssureRidge Cyber is an easy place to start.