Considering the importance of invoices, you’d think that we freelancers would do everything possible not to make any mistakes. However, such is not always the case. In fact, invoicing errors are more common that you might think.

When it comes to invoicing mistakes, you get a wide range: everything from a simple typo to a missed marketing opportunity to accidental illegal conduct! And whether you’re guilty of one of the “biggies” or not, you’re likely making at least one of the 12 common mistakes on this list.

1. Sending the Invoice to the Wrong Person/Department

If you’re juggling multiple clients, it can be all too easy to get them mixed up. At best, you’ll end up embarrassed (and have to wait a little longer to get paid). At worst, you could end up violating your contract by divulging your client’s private information to another party – which could potentially land you in an expensive legal snafu.

On the other hand, if you’re invoicing a larger company or multi-person office, you may face a different sent-your-invoice-to-the-wrong-person scenario. When it comes to larger businesses, the person you’ve been corresponding with may not be the person who’s ultimately in charge of paying you. The easiest way to find out who is the person who pays you? Ask – and then address your invoice accordingly.

2. Not Itemizing

You always want to reiterate what your client is paying you for. Of course, the level of detail that goes into that itemization is up to you. You can itemize using large, general terms (“blog post” or “site design”) or you can break it down into the nitty-gritty details (“two 500-word articles on deforestation” or “one WordPress website with rotating slideshow and shopping cart widget”).

The main point is to be specific enough that you and your client can easily keep track of exactly what’s being paid for.

3. Not Proofreading Before Sending

Is everything spelled right? Is the currency right? Did you do the math right? Did you remember everything? These are all questions you should ask yourself before sending your invoice.

Double-check your invoice for typos and accuracy. Not only will this help to ensure you look as professional as possible, it will increase your chances of being paid the right amount for the right work. Because there’s nothing quite like being paid in the wrong currency due to a careless invoicing error. Triple-check your info!

4. Not Invoicing as Soon as Possible

Don’t jump the gun but don’t wait for your client to forget you either. Send out an invoice after each completed milestone of a project. Or, immediately upon finishing your project.

Sending invoices promptly increase your chances of getting paid on time as well. Conversely, late invoices result in late payments. Speaking of which…

5. No Due Dates

Sending out your invoice “on time” is almost meaningless if you don’t tell your client when you expect to be paid by. Never send out an open-ended invoice. Always include a due date, even if that date is far into the future. (I don’t know why it would be, but that’s your choice.)

Pro tip: a specific due date is better than saying “due in 30 days.” When you make your due date a non-specific place in time, your client won’t connect with it as much as a “real” deadline. Give them a “tangible” date to hold onto in their mind.

6. Not Restating Your Terms

What are your policies in regard to revisions? How many weeks of additional support do you offer? How do you handle refunds and returns – and how many days do your clients have to ask for one?

You’ve likely already covered these in your initial contract, but, just as it’s a good idea to reiterate what your client is paying for overall, it’s also a good idea to briefly restate your terms/policies. Scope creep isn’t exclusive to the duration of the project. In fact, many clients wait until after a project is “over” to start making additional demands on your time. By restating your policies within your invoice, you continue to set professional boundaries, showing your client exactly how you want to be treated.

7. Not Following Up on Late Payers

Just because you sent an invoice doesn’t guarantee that you’ll be paid on time (or at all). That said, there’s no reason why you shouldn’t follow-up and continue to pursue this client within reason.

“Within reason?” Yes, within reason. For more on what I mean by that, check out “A Practical Approach to Dealing with Late Payers“.

8. Not Putting Your Logo on Your Invoice

Just because your invoice is essentially the last step in a long freelancer/client process doesn’t mean that you should skimp on its look. Your invoice, just like every other piece of correspondence you’ve sent, should reflect your branding and professionalism as a whole.

Better yet, use your invoice as a branding opportunity. Slap your business logo on there! Type your web address and tagline in the footer. Don’t go overboard, but do enough to remind your client of exactly who they’re dealing with – and why your business should stick out in their mind as the one with the best service.

But, of course, still use your name. This is a legal document. Don’t get too carried away with the passive marketing opportunities!

9. Not Stating How You Want to be Paid

Never assume that your client knows how you’d like to be paid. If your client is in China and you’re in America, you’re not going to want to wait a month for a check to come to you in the mail! You’d most likely prefer an online payment via PayPal or something similar.

Speaking of which, you should also make it as easy as possible for your clients to pay you. Embrace modern technology and start accepting electronic payments.

10. Not Saving (or Backing up) Your Invoices

These are some of your business’ most important documents. Back up your files. You never know when you may need to return to them later, for tax purposes or to settle a dispute.

11. Adding on Undiscussed Fees

One of the quickest ways to get on a client’s bad side is to tack on a list of previously undiscussed additional charges. Your client should never be taken by surprise by what they’re to be paying you. All fees should be either listed in your policies up front or discussed ahead of time. And never, ever, purposely try to pull one over on your client by ripping them off.

The best way to ensure additional charges don’t come as a surprise is to tell your client about them before you actually do the work. If your client requests something outside of your agreed-upon scope, let them know, and tell them that if you continue forward on that path that you’ll have to charge extra. Give them a chance to back out. If they choose to proceed then you may add on your fees to your invoice guilt free (though, to avoid confusion, I recommend listing them as a separate item).

12. Not Invoicing at All

Never, ever assume that your client knows what’s going on when it comes to paying you. Not because they’re stupid or because they’re trying to scam you (though that does happen), but because they, like you, are incredibly busy professionals. They have a lot on their mind and a lot to keep track of.

Your getting paid is ultimately your responsibility. And the first step toward owning that responsibility is sending out an invoice.

The good news is, creating and sending invoices is easy. Especially if you use an invoicing software like Quaderno.

You have no excuse not to send an invoice. And, in keeping with the theme of this article, it would be a huge mistake not to!