The short answer
Secure the affected account, freeze credit with each bureau, and preserve recovery information after personal data is exposed.
Step by step
Change the breached account password and any reused passwords from a trusted device.
Place a security freeze separately with each major credit bureau and save every PIN or recovery method.
Review bank, card, carrier, and credit reports for unfamiliar activity and enable transaction alerts.
Secure your email and carrier accounts with stronger multifactor authentication and a number-transfer lock.
Keep the breach notice and a dated record of reports, freezes, calls, and disputed activity.
Before you finish
Keep screenshots, receipts, chat transcripts, confirmation numbers, and the first bill after a change. Carrier terms and account eligibility can change, so verify the final price and conditions directly before submitting an order.