Before you hit record on a call or conversation, the law cares who has to agree. Federal law and most states let one party consent; a number of states require everyone on the line. Pick what you're recording and your state to see the rule — plus how cross-state calls and recording police in public are treated. General information, not legal advice.
Under federal law and in most states, if you are part of a conversation you can record it — that's 'one-party consent.' A number of states require that everyone being recorded agrees first ('all-party' or 'two-party' consent), and recording without that consent can be a crime as well as grounds for a lawsuit. The rule turns on whether the people speaking had a reasonable expectation of privacy.
When a call connects people in different states with different rules, the safe practice is to follow the strictest state's law — get everyone's agreement on the recording. Recording police officers performing their duties in a public place is a different question: every federal appeals court to decide it has treated that as protected by the First Amendment, as long as you don't physically interfere. You can be asked to step back, not to stop recording.
This shows whether your state lets you record a phone call or conversation with just your own consent, or requires everyone being recorded to agree first. Each value is cited to the state statute or agency; a state with no sourced figure shows "Not yet sourced."
General information, not legal advice. Rules change and exceptions apply — confirm the current rule with the cited source for your state.
Disclaimer: NotALawyer.com provides general legal information, not legal advice, and is not a law firm. Using a tool does not create an attorney–client relationship. Laws change and vary by situation — verify anything important with the official source or a licensed attorney in your state.