Does my friend need assistance filling out visa paperwork to get to the UK?
It sounds weird. No offense at all but your friend might need some excuse to ask for B20000. Otherwise that translator or company is a scam. Even if your friend has a decent regular job and financial back ground, it’s far easier you come to Thailand to help her/him applying for UK visa. Unless she/he has, better give up inviting her/him. Be careful.