'F**k you money' is the hack you need to leave a toxic job.

There's a clip that grabs my attention every time it goes viral online: Lucy Liu, cool as ever, casually explaining to an interviewer the importance of "fuck you money." 

"I worked a lot in order to just have money. It was called 'f**k you' money. 

"If you have it, and something's not working out, and they say you have to take this job, or you're fired, you can be like, 'f**k you.'"

It's glorious, and even more because she's absolutely right.

Watch more about Lucy Liu's 'fuck you' money strategy. Post continues below.

FU money stops you from being trapped – in a bad relationship, in a bad job, or any bad situation. 

In a moment where it's all hitting the fan, it gives you choices. The opportunity to find somewhere new to live, keep paying your bills, and find a better situation without the stress of life's financial realities crashing in on you. 

The best part about FU money, is that just having it means that you rarely need to use it. 

If people know that you have the ability to walk away, they often treat you more respectfully from the start. 

But okay, sometimes your bluff will be called, and you'll have to decide if it's actually time to use your stash. In that case, the question is how much you will actually need.

It's something of a 'how long is a piece of string' question, or rather, how big an FU do you want to deliver? 

Here's how to figure it out.

Level 1: The 'breathing space' FU money.

What it looks like: About three months of core expenses.

At the most basic level, FU money might mean just enough cash to cover the necessities — rent, groceries, basic bills — for a few months. 

I'm not talking three months of your pay, but three months' worth of the core expenses that you can't avoid paying in that time. 

Add up your non-negotiables every month — rent or mortgage, utilities, groceries, basic transportation (not including your commute). Multiply by three. That's your Level 1 FU money target.

Then if you get a horrible new boss? Or a client who makes your skin crawl? 

You can pull the pin and walk out that door, without having to frantically start job-hunting the very next morning.

You can even stretch this money a little further by taking on freelance, part-time, or lower-paid jobs in the meantime. 

It's the smallest taste of FU freedom. Just enough to remind you that life is more than tolerating nonsense from those who don't respect you.

Level 2: The 'recover and refresh' FU money.

What it looks like: Roughly six months of salary.

Now you're hitting the zone where you could afford a real break.

Depending on how bad the situation got before you pulled out your FU stash, you might need to recharge, and clear your head. If you've got six months of your salary tucked away, you can pull the pin on the toxicity, and even travel for a bit for a full reset. Figure out your next move at a seaside café rather than in a stuffy office.

This level lets you be more selective. You don't have to jump into the first job offer you get, but can be intentional about hunting out something that aligns with your values, or truly interests you. 

You could even hit pause in order to upskill, take a course, or start a small business that you've always suspected could be a winner. 

You've got the time to truly step back, reassess and then take a confident next step forward.

Level 3: The 'I might go back to work when I'm bored' FU money.

What it looks like: A solid six-figure investment portfolio, worth around two years of salary.

At this stage, you're not fully financially independent, but you're getting close. It's not enough to live off forever, but you've got enough to fund a mini-retirement, if you want to change gears in your life.

You could take a couple of years out of the workforce without sacrificing too much of your lifestyle. Perhaps spend the time with your kids while they're young, dive into a passion project, or try out a couple of different career paths you've always wondered about but weren't ready to fully commit to.

You'll need to head back to career mode at some point, but it'll be on your terms, and your own timeline.

Level three can act as a bridge that takes you from one life stage, to a new one, without the fear of financial collapse. 

Level 4: The 'you're never telling me what to do' FU money.

What It Looks Like: Around $1 million or more, invested.

Now we're talking about true financial independence, where you could walk away and just live off investments instead.

A rule of thumb in the personal finance world is that if you put your money into something like a share market index fund, you can take out 4 percent each year, without eventually running out.

So if you have a million dollars invested, that's about $40,000 a year that you could spend. Don't forget, your work life often costs you in transport, clothes, training, and food on the go, so that number could work quite well for a retired life.

At this level, work becomes a choice, instead of a necessity. You can look for fulfilling projects, and negotiate your rate at leisure, knowing that it's a nice-to-have, instead of a need. 

Even better, at this level, you rarely have to say "f**k you" at all. Why waste breath on negativity when you can simply avoid people and scenarios that drain you? You're focused on finding the good stuff in life, and enjoying it, not being forced into choices out of financial fear.

Choose your own adventure.

The different levels show us one thing pretty clearly: there are different paths to do it, but there's a version of FU cash that can work for almost anyone.

Really, it's less about the option of being able to throw deuces at the boss on your way out the door, and more about the ability to take control of your own path through life.

It's about making life decisions that are less driven by fear or necessity, and more by what enriches your days.

Lucy Liu was spot on; everyone should want FU money, and have their own version of it stashed away… just in case.

Frances Cook is an independent journalist, and qualified as a financial adviser. You can get more financial tips and tricks by tuning in to her weekly podcast Making Cents, on YouTube, Apple Podcasts and Spotify.

Feature Image: Twentieth Century Fox.