As a business owner, you have to overcome numerous hurdles. One of the hardest ones that I've struggled with in the past is getting paid.

After all, you worked hard on delivering top-notch work to your client in a timely and professionally manner. And, you're relying on that payment to keep a positive cash flow in order to keep your business operational. The absolute last thing that you want is to get screwed over.

But, sometimes that's the reality of being a small business owner.

At my company, we recently analyzed over 230,000 invoices that have been sent. Only around 84% of invoices are ever paid. That leaves 16% of all the work small business owners do unpaid. While most invoices were paid, we took a deeper look at why the invoices were not paid and what you can do to ensure you're not working with other businesses that won't pay their bills.

Here are 16 telltale signs that your invoice will not be paid based on data we've collected from countless delinquent payers and how to fix the root of the problem.

1. The Client Has Been Disorganized From The Start

Has the client been disorganized from the moment you've met them? You know, being flaky when it comes to communication, throwing together a half-hearted explanation of the project, and generally being all-over-the-place.

This isn't just frustrating while working on a project, it's a pretty good sign that they're not going to pay your bill because it's either been misplaced, accidentally thrown away, or they've so frazzled that they've completely forgotten all about it.

2. Contact Information Looks Fishy

Perhaps the worst type of non-paying client are the crooks who have never intended to pay you for your goods or services. Sometimes they're so sneaky that you can't spot them, but sometimes it's pretty obvious.

If they have email accounts that look unprofessional or spammy or provide with a post-office box and mobile number for contact information, then those are some obvious red flags that they're not legit.

3. There's a Lack of Communication

When's the last time that you heard from the client? If it's been weeks/months, then that's never a good sign.

If they don't respond to your emails or phone calls in a timely manner then they're most likely dodging you because they know that you're trying to track them down for a payment.

4. The Client Is Indecisive

Indecisive clients are difficult to work with because they never know exactly what they want. Instead of providing you with feedback during the course of a project, there's just a bunch of uncertainty and contradictions.

If they're dissatisfied with the final product do you think that they're going to pay it when they receive an invoice?

5. They're Extremely Nitpicky

Another type of client that can trigger migraines are those who nitpick. To be fair, I understand that it's their business and they want things done a certain way. That's why they have sent you a clear explanation of what they're looking when hiring you. At the same time, you're the expert and know the ins-and-out of your industry. That's why they hired you in the first place.

With that in mind, if you have a client that is particularly nitpicky and is constantly asking for adjustments or revisions, then there's a good chance that they're not going to be pleased when you hand in the final product. And, if they're happy with your work, they're not going to willingly pay your invoice.

6. There's No Accounts Payable Department

If you're dealing with a solopreneur or small business, there probably isn't an accounts payable department. That can be a concern because since they're juggling so many responsibilities, your bill can become a low priority for them. Try to make sure you're dealing with a real company with a billing dept.

7. You Don't Have a Contract

The reddest of flags is probably when a client refuses to sign a contract. Remember, this written agreement just doesn't explain the scope of the project and how you expect to be paid, it can also be used to your advantage if you decide to take legal action against the non-paying client.

8. The Client Only Wants To Pay With a Check

It's no secret that if you want to get paid faster then you need to accept multiple types of payments from cash to credit cards to Bitcoin. But, if you have a client who demands that they pay you with a check means that they could be trouble.

Unlike credit cards, which you could keep on file for recurring payments, paper checks give the client the power to establish their own grace period or keep writing bad checks.

9. "The check is in the mail" or "Send me the invoice again."

These are the type of responses that you'll hear from deadbeat clients who have no intention of paying you. They're just giving you the runaround so that you can get off their back for a little while since you can't prove otherwise.

10. The Last Check Bounced

In my early days as a freelancer, I accepted a check from a client. It bounced. They said there was a mix up at the bank and sent me another check. Guess what? That check bounced too. Lesson learned.

While there could be a mix-up once in a blue moon if the last check that a client sent you bounced then that's a good indication that they have no intention of paying your invoice. If you haven't noticed by now, it's probably a good idea for you to move away from paper checks and accept payments that will actually process.

11. They Ask For Spec Work

Spec work is when any kind of creative work is submitted to a client before they've officially made the decision to hire you. While there are instances of legit clients who use spec work to see if you're a good fit for them, spec work if often a big no-no for freelancers. In most cases, clients don't intend to pay you for the time and money that you spent working on this little project.

If they request spec work, redirect them to your portfolio, experience, and testimonials.

12. They Lack A Basic Understanding of the Value That You Offer

Another challenging client is the one who doesn't understand the value you provide that you provide to your clients, as well as the effort and skill required to do the job well. You'll notice this when they say things like "This shouldn't take you long" or "Can you design a quick poster?"

When they downplay this, they'll question the time you spent working on their project and the rates that you charge. If they think you're overcharging them, they're definitely not going to pay your bill.

13. Registered Letters Are Returned or Unclaimed

One of the most common, and often effective, ways to collect late payments is by sending the client a registered letter. But, what if they don't sign the letter or it's returned? That's a red flag that the client is going to bail on the invoice payment.

14. The Client Objects to the Goods or Services You Provided

What if you finally get in touch with the client and they suddenly have objections that were never stated before? Again, that's a telltale sign that they're making any excuse possible to not pay the invoice. A legit client would address any questions or concerns before everyone reached this stage.

15. They Request Invoice Paying Deadline Extensions

There's a reason why you and the client agreed on certain terms; it ensures that you get paid on a specific date so that you can set budgets and maintain a healthy cash flow. This is always discussed during the negotiation phase of a project. That's why if the client continually asks for an extension, then you know that something's afoot.

I will say, that sometimes the unexpected happens. And, there's a chance that your client may have fallen on tough times. As a sign of good faith, however, the client will at least try and work out some sort of payment plan with you instead of pushing back the due date or asking for extensions.

16. They're Hesitant

Don't force a client to commit to a project if they're uncomfortable. While landing a new gig should be one of your priorities, this is a situation that could backfire. If they've been hesitant from the get-go, then don't be surprised when the client isn't satisfied with your work or ignores your emails and phone calls since they weren't onboard from the moment that project started.

Dealing With Deadbeat Clients

If you want to ensure that your invoices are paid, you can overcome deadbeat customers by;

Be selective about your clients.
Always receive an upfront payment.
Add interest to overdue payments.
Withhold certain services or property.
Take legal action.
Cut your loses.
Published on: Mar 30, 2017
The opinions expressed here by Inc.com columnists are their own, not those of Inc.com.