HMRC introduced this to the SEIS/EIS application process to deter speculative applications from companies that weren’t yet ready to raise.
There’s no obligation for the investor you name to actually invest. You can change the name of the investor and their investment amounts at any time. But don’t just make an investor up. It’s better to find investors who are, on balance, likely to invest and to get their permission first.
To see who’s eligible to invest under SEIS and EIS, go to SEIS rules for investors.