I just bought a used 5th wheel in Kansas and brought it home to Texas. I did the title transfer, paid the sales tax, and registered it this past Thursday.
most of what has been said here is correct. Here is the way it worked on Thursday, and what I learned that day.
1. You can pay tax and get title in any county tax office in Texas
2. You must REGISTER it in the county you reside in.
3. Sales tax is 6.25% based on the price, less any trade-in
4. If you have an empty weight on the out-of-state title, you do not need to have trailer weighed. If no weight listed, you must have a weight ticket to show. Note: some tax office clerks think a new weight ticket is always required. That info is incorrect. Kindly suggest they call Austin for clarification if they demand to see a weight ticket and the weight is on your title already.
5. You need a bill of sale, the title, and any dealer paperwork showing pricing, trade in, etc.
6. You need to have the trailer inspected and a copy of the state inspection form showing it passed the safety inspection
7. You do NOT have to show any type of "proof of insurance". Some tax office workers do not know this, so as a precaution, take a copy of the insurance for your tow vehicle.
8. Fill out a Tx. DMV form #130u. This is the form for title application. It is avail online.
9. Pray you get a knowledgeable tax office clerk, and pray that they are in a good mood.
10. Be polite, no matter what, but be firm if you know you are right and they are wrong.
Good luck.