TaxJar is pretty darn good at it what it does

Overall Satisfaction with TaxJar

We use TaxJar to accurately calculate our sales tax requirements from our Amazon sales. TaxJar has a pretty seamless integration with Amazon and, come tax season, we're able to see how much sales tax we collected from the various states where we have a nexus allowing us to easily file and pay our sales tax requirements.
  • Even though it was 4 years ago, I remember the integration process with Amazon being incredibly simple. TaxJar provided instructions on exactly what to do in order to make sure they were receiving the correct data. Even someone with zero IT or technical skills can follow the instruction and get it working. And it has worked pretty perfectly ever since.
  • TaxJar does a great job of having a dashboard that makes it simple to see your gross sales, your taxed sales and what you owe in each state. If there's a new state where you haven't filed, TaxJar has an excellent guide on how and where to register for that state.
  • TaxJar offers Auto-filing so that if all of your marketplace sales are tracked via TaxJar, then you don't even need to take care of filing your sales tax. They'll do it for you. I personally don't use it, but it's great that they offer it.
  • One thing is that I do sell on another platform that integrates with TaxJar, but I have products that are exempt from sales tax in some states. With the other integration, there's no way to show those products as exempt. It seems that TaxJar doesn't see those exemptions for some reason.
  • Support is only via email, unless you upgrade your plan to TaxJar Plus. During filing season that can be really stressful if you need answers quickly.
  • It would be great if TaxJar could notify me if I have nexus in a new state, so I don't have to check on my own. Right now it has to be checked manually.
  • With regards to ROI, it definitely saves time. And time, as they say, is money. It may be hard to put a particular dollar sign on this, but it definitely has provided a positive return.
  • It keeps me aware of where I have sales tax nexus that I might not know about otherwise. This is important. Even if I have to check it manually, at least I am made aware of where I need to file.
  • It allows me to track how much in sales tax we've paid year over year, which is a good indication of how our sales are doing.
I have not used any other products like TaxJar. I'm not even sure who the competitors are. I'm sure that they are out there, but this was the first one I found when looking for providers that worked with Amazon, and since it worked so seamlessly I never bothered to look for another provider.
Even with a few minor issues, TaxJar is still a great service that makes calculating sales tax from your marketplace sales MUCH easier than having to do it manually. For Amazon, it's a no brainer. There are a lot of other marketplace integrations that may work just as well, or less so, but I can't speak to those yet as I am not using them currently.