I'm a web application developer. For over a year I worked productively with this client. We even made a follow-on contract.

One day, not even two months after the follow-on contract, my client suddenly came in for an escalation meeting, telling me he would need to forward my services to one of his business partners. He said that I wasn't performing as expected, which was the first time I heard that from him. We had meetings before in which he praised me and my results.

Me: Well that's a surprise. I'll have to think about it. 

Two days later, I had thought about it and told him I did not want to forward my services.

Client: Well I can see if we have another project you can work on. But if not, I will have to terminate our contract.

Three days later, he calls me:

Client: I'm calling to ask if you can reconsider forwarding your services to our business partner. We have something special planned for you there.  

He continued to tell shady details about how he wants an insider at his business partner to enable him to take them over. Basically I would be working for him as a spy. 

Me: Well I'm definitely not comfortable with that. 

Client: Don't tell anyone. This call and everything said falls under our NDA. Think about it, ok?

I did not hear from him for a week and continued doing my work according to our contract. One Monday I had an email in my inbox - written at Sunday evening - stating that he is sorry to tell me that he has to terminate our contract. The attached termination letter (I also received in print via mail two days later) was dated back at the date of the escalation meeting.

As our contract stated, that one side cannot terminate the contract without proper reasoning, I filed a suit. Three weeks went by with a lot of back and forth between my lawyer and his resulting in him withdrawing the termination.

During this process, even Even his lawyer said the client was difficult to work with

I used that lawsuit as my valid argumentation to fire the client shortly after and could enforce indemnity claims as well as other compensations.

Happy Ending. Always have a good contract.

Client: Hi. Do you do Photoshop? 

Me: Yes, I'm proficient with Photoshop. How can I help you? 

Client: I wanted to know if you do logo editing? 

Me: Logo editing? 

Client: Yes. I have a professionally-made logo, and I need it edited.

Me: I see... Well, what changes are you looking for? 

He sent me a low-res logo with a watermark.

Client: I need the semi-transparent thing over the main picture removed and the blurry edges made better.

Turns out, this client from hell had contracted a fellow artist - who is a friend of mine - to design a logo. The client bargained his way into paying 10% upfront instead of 50% like my friend usually charges, then after he was satisfied with the logo (which still had the watermark), he thought he'd be clever and tell my friend his work was inadequate and wouldn't pay the remainder. 

Unfortunately for him, the first person he tried was me. I immediately informed my friend, who warned the client from hell not to try using his work without paying. 

Client from hell ignored the warning, presumably found some other guy who was willing to turn a blind eye and help him (badly) remove the watermark, then used the blurry low-res image anyway. My friend tried lawyering up, but apparently, it wasn't worth it. Now he refuses to waver from his 50% upfront policy.

Client: I want you to get increase our customer base and get our existing customer to register for charity competitions.

Me: We can construct a content marketing plan to build authority and engage the audience, driving them to your website. We can try marketing to your existing audience to encourage sign-ups for your charity competitions and use the Charity fundraiser story to tell the story of the brand.

Client: Sounds great.

Me: Oh, I'll need access to your website to redesign it so that there are clear calls to action, sign up forms with eCommerce and design landing pages for various campaigns.

Client: You can't have access to the site until the developer has finished with it, at the end of the month.

Me: OK, why not direct them to add these changes while they are still under contract to complete the site.

Client: Will do.

Two months later:

Me: I haven't seen any updates on your site. Can I at least have access to your client database so we know who we're marketing the charity competition towards? 

Client: You will at the end of this month.

Me: Fine, but your first charity competition is now only several weeks away. We don't have much time to generate registrations AND the site still has no call to action or e-commerce registration forms so we can't grow the database.

Client: The web company owns the website. We will never have access and we can't afford to ask them for updates. There is no client database. We need charity registrations now or the company won't survive!

Me: What? why are you only telling me this now? No database? What have you been doing for the past year? Oh, and your third invoice payment is late again, will you be paying this now?

At this point, the client "lost my number" and stopped responding. Eventually:

Client: We don't want to work with you anymore and won't be paying you. We expect results immediately.

Me: But you signed a contract stating you understood content marketing results would be at least six months. If you are canceling fine, but there is a 30-day notice period. I need this in writing.

However, I'd noticed something else weird about his business at this point: he'd run his first charity event, and was funneling the charity money back into his business. I decided to bring this up: 

Me: I don't understand why you needed the charity event grossing 5,000 to keep the company afloat, are you not giving the money to the charity?

Client: We want to sue you for loss of earnings as the charity cost 10,000 to run and your content marketing isn't working fast enough.

Me: So you spent 10,000 with target earnings of 5,000 for yourself and passing it off as a charity event? You think something that will take six months to work should happen immediately and I'm to blame?

Client: Yes.

I worked at a hospital but did tech support on the side for many of the people that I worked with. One of these clients was a doctor that would still randomly bring up his high school football days in the most annoying braggadocious ways. As unpleasant as he was, he paid well, so I helped him numerous times.

One night I get a frantic text from him saying he needs immediate tech support:

Client: Can you fix a piece of paper if I give you a copy?

Me: Yeah, I can scan it in and photoshop it.  Is this for work?

Client: Not exactly.  Can you add text in?

Me: It depends...

Client: My wife asked me for a copy of the phone bill and I need a couple of numbers removed. *sends file*

It turns out that he had been having an affair and had been calling her on his cell phone a dozen or so times a day.  His phone bill was three pages long of small text and over half of it was phone calls to her. 

I was tempted to alter the file, charge him a hefty fee, and put in some watermarks stating this was an altered bill.  Instead, I took the high ground and ghosted him.

I ran into him recently and you'll be happy to know that his kid (from his ex) is "GREAT AT FOOTBALL."

I was helping an elderly business owner with marketing.

He seemed nice at first.

Client: I hear so many complaints from customers, I am immune to it by now. I feel like a surgeon, and after a while, it just feels like business as usual.

Me: I’m sorry to hear that. It’s important to get their complaints resolved as soon as possible these days, as customers provide feedback online.

Client: I don’t have time to figure out their concerns. I am providing useful products and services. This is how I run my business.

Soon after, I walked away after seeing countless complaints come in daily that weren’t even close to resolved.

A year later, I read in the newspaper that shortly after I left, there was a class action lawsuit against him for failing to provide basic levels of safety in his products and services. I am glad I was not involved.

I'm a designer for a large company. One day, a freelancer we often worked with sent me a heads up that they had found a suspicious project brief on one of those "design contest" websites (red flag #1).

I went to the contest website, and saw that this client wanted a label designed for a product that was similar to my company's Product A (red flag #2). No big deal, though. We have plenty of competitors in that space.

I looked at the assets the client had provided, and discovered that their logo looked very "inspired by" my company's logo (red flag #3). Same colors and lockup.

Then, I opened the client's creative brief, and beheld a word document with just two photos:

1. My company's Product A, with arrows directing designers to text they should replace with the client's company info.
2. My company's Product B, with a "change color scheme to this label" next to it.

Shaking my head at the cluelessness of some people, I couldn't help but peek at the designs that had already been submitted. There were eleven, and every single one of them looked like a bootleg version of Product A. I had a good laugh and then called the legal team.

I can't help but feel bad for the designers who took the time to work on this, since none of them are going to be paid. Last I checked, the contest page was blank except for "This contest is locked because [client] has asked for a refund."

I was designing a local newspaper advertisement for a restaurant. The client wanted a large photo of their restaurant so it would be easier to find.

Client: On the window it shows our Food Hygiene Rating of 2 stars. That doesn't look good for the advert so can you Photoshop 5 stars instead?

Me: That's not only dishonest, but illegal.

Client: So what? We deserve 5 stars.