RE License Needed to Invest in TX?

[Tasha Beal]

I have recently began looking into real estate investing, and I am a bit confused about when you need a RE license. I've heard it varies by state, but what do I need a license for in Texas? I am planning on investing in buy&hold properties, but if I want to sell it a few years down the road, would I need a license for that? 

In general, do you recommend having a RE license as a real estate investor (buy&hold and flipping in particular)? Thanks in advance!