Same here. I called the courthouse (three times, just to verify) to see if he needed anything or if we needed any special paperwork beforehand. All he needed was his passport, but he had his driver's license and birth certificate, just in case.
Terri made a good point, though - have your intended get a note from their employer (or, if not employed, bring a lease agreement / mortgage papers, etc.) on the off chance that Immigration may get suspicious. Never lie to immigration! If they ask about marriage be honest, but don't volunteer the information if it's not sought after!
Is it really cheaper, though? If you get married in the UK you have to pay for the Fiance(e) Visa, but if you skip that bit and have them come over here to get married you'll have to pay for the extra flight (I suppose it also depends on how far you / they have to fly). I'd think it would sort of come out even, give or take. But not having to go through the hassle of that additional Visa certainly makes things easier.
Good luck!
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