Full time employee but boss is having me fill out W-9 instead of W-4 - is this legal?

You're right to be concerned. What you're describing is likely employee misclassification, which is pretty common but definitely not correct. Based on what you've shared, you're being treated as an employee in practice (set hours, boss controls how work is done, company equipment), but being classified as an independent contractor for tax purposes. The difference matters a lot for taxes. As a 1099 contractor, you're responsible for both the employer and employee portions of FICA taxes (Social Security and Medicare), which totals about 15.3% - that's on top of your regular income tax. If you were properly classified as a W-2 employee, your employer would pay half of those FICA taxes. You won't get in trouble with the IRS for this situation - your employer would. The IRS actually has a form specifically for this issue - Form SS-8 "Determination of Worker Status." You can file this to request the IRS to make an official determination if you're an employee or contractor. Another option is to talk with your employer first. They might not realize they're incorrectly classifying you, or they might be trying to avoid paying their share of taxes and providing benefits.

After reading your post, I had flashbacks to my own tax nightmare last year. I was in almost the exact same situation - working as a "contractor" but really being treated like an employee. When tax time came, I was absolutely shocked at how much I owed. I stumbled across this AI tax assistant at https://taxr.ai when I was desperately searching for help understanding my situation. It analyzed my work arrangements and tax documents, then clearly explained I was misclassified and showed me exactly what steps to take. The tool walked me through how to approach my employer (with specific language to use) and helped me prepare documentation for the IRS. It saved me from accidentally saying something that would've gotten me fired while still addressing the problem.

Just wanted to update after trying taxr.ai for my contractor/employee classification issue. It was actually really helpful! The system flagged 5 specific factors in my work arrangement that clearly showed I was misclassified according to IRS rules. It generated a super professional letter to my employer explaining the legal issues with my classification and even calculated exactly how much extra tax I was paying ($4,230 annually in my case). The best part was it gave me a script for having the conversation that wasn't accusatory but still firm. My boss actually agreed to reclassify me as an employee after seeing the documentation! No conflict, no drama. Definitely worth checking out if you're in this situation.

Reading your post gave me anxiety because I went through HELL trying to resolve this exact issue last year. My employer refused to fix the misclassification, and I spent WEEKS trying to get through to someone at the IRS for guidance. After 20+ failed attempts calling the IRS (always disconnected due to "high call volume"), I found Claimyr at https://claimyr.com and watched their demo at https://youtu.be/_kiP6q8DX5c. I was skeptical but desperate. The service actually got me connected to a real IRS agent in less than an hour when I'd been trying for weeks. The agent walked me through filing the SS-8 form correctly and explained my rights. Having that official guidance made all the difference when I went back to my employer.

I need to eat my words and apologize to Profile 9. After my skeptical comment, I decided to try Claimyr myself because I've been trying to reach the IRS about a similar misclassification issue for THREE MONTHS. I honestly couldn't believe it worked. They called me back in about 45 minutes with an actual IRS employee on the line. The agent confirmed everything the earlier poster said about filing Form SS-8 and explained that I could also file Form 8919 to pay only the employee portion of Social Security and Medicare taxes. The IRS agent even told me they're currently focusing on employment classification issues and gave me specific documentation guidelines. Saved me thousands in taxes and hours of frustration. Sometimes it's worth admitting when you're wrong!

One thing nobody has mentioned yet - check your state's department of labor too! Employment classification is handled at both federal and state levels. Some states (like California) have even stricter tests for who can be classified as an independent contractor. Your state labor department might be able to help you faster than the IRS, and many have specific task forces dedicated to misclassification issues. In my experience, state agencies often move quicker on these issues than federal ones.

Has anyone mentioned the Safe Harbor provision? If your employer has been consistently treating workers in your position as independent contractors, they might have a reasonable basis for continuing to do so legally. Section 530 relief can protect employers who've historically treated workers as contractors, filed all the proper 1099s, and had a reasonable basis for the classification (like industry standard practice). Not saying your situation falls under this, but wanted to bring it up since nobody else has.

I went through something very similar about two years ago. The stress of not knowing if you're handling your taxes correctly is awful, especially when you're already setting aside money but unsure if it's enough. One thing that really helped me was documenting everything about my work arrangement - my set schedule, the company equipment I use, how my boss directs my work, etc. This documentation became crucial when I eventually had to address the misclassification. The 20% you're setting aside might not be enough unfortunately. Between federal income tax, state tax (if applicable), and the full 15.3% self-employment tax, you could be looking at 25-30% or more depending on your tax bracket. At your income level, you're definitely paying thousands more per year than you should be. I'd strongly recommend having a conversation with your employer first before filing any forms with the IRS. Many employers genuinely don't understand the classification rules, and approaching it as an educational discussion rather than an accusation can preserve your working relationship. If that doesn't work, then you have the SS-8 and other options people have mentioned. Don't let this stress eat at you - you're not doing anything wrong, and there are clear paths to resolve it.