Starting your second heist in GTA Online depends on whether you’re talking about the original story-mode heists (like the Merryweather Heist in single-player) or GTA Online heists (multiplayer). Since your question mentions “GTA 5 Online,” here’s how to begin your second Online heist after completing the first one.

Prerequisites for Heists in GTA Online

Before you can start any heist (including your second one), you must meet these requirements:

  • Own a high-end apartment (with a heist planning room). The cheapest is Del Perro Heights, Apt 4, for $200,000.
  • Be registered as a CEO/MC President (via the Interaction Menu > Register as a Boss/President).
  • Complete the first heist (Fleeca Job) and wait for Lester to call you about the next one.

How to Start Your Second Heist (Online)

Once you’ve finished the Fleeca Job (your first heist), follow these steps to start the next one:

  1. Wait for Lester’s Call
    After completing the Fleeca Job, Lester will eventually call you to offer the next heist (usually the Prison Break).

  2. Go to Your Heist Planning Room

    • Enter your high-end apartment.
    • Walk to the heist planning board (marked with an “H” on your minimap inside the apartment).

  3. Start the Heist

    • Interact with the planning board.
    • Choose “Start Heist as Leader” (you must be registered as a CEO/President).
    • Select the next available heist (e.g., Prison Break).

  4. Invite Crew Members
    Most heists require 2–4 players. Invite friends or use matchmaking to fill roles (e.g., hacker, driver, gunman).

  5. Complete Setup Missions
    Before the finale, you’ll need to complete several setup missions (e.g., stealing disguises, acquiring weapons).

  6. Launch the Heist Finale
    Once all setups are done, return to the planning board and start the finale.

Alternative: Join Someone Else’s Heist

If you don’t want to host, you can join another player’s heist as a crew member:

  • Open your phone > Quick Join app > select Heist.
  • Or, if you own a heist property (e.g., Facility, Arcade, Kosatka), stand near the planning screen and press left on the D-pad to join as a crew member.

Heist Progression Order (Original Online Heists)

The original heist storyline progresses as follows:

  1. Fleeca Job (2 players)
  2. Prison Break (4 players)
  3. Humane Labs (4 players)
  4. Series A Funding (4 players)
  5. Pacific Standard Job (4 players)

Tips for Success

  • Communicate with your crew (use voice chat or pings).
  • Stock up on snacks/armor before finales.
  • Choose roles wisely (e.g., best hacker for more time, best driver for escapes).
  • Replay heists by calling Lester or Pavel via your phone if you want to redo them.

TL;DR: After finishing the Fleeca Job, wait for Lester’s call, go to your apartment’s heist planning board, register as a CEO, and start the next heist (Prison Break). Make sure you have a crew (2–4 players) and complete all setup missions before launching the finale.

Information gathered from public forums or data available on the internet and portrayed here.