Wife and I just got our TX licenses a few months ago. Here's what the DPS told us: if you have previously had your BC scanned into their system, you do not need it. If I didn't know for sure they had scanned it in, I would take it with me. They also asked us for some paid bills at our address and SS cards. My wife did not have her SS card, but had a tax doc that showed her number, and the nice lady accepted that.
The clerks at the office would make an announcement about having your BC every few minutes and half the folks waiting would sigh, get up, and leave. At least they offered to hold their place in the 'line" for when they returned.
