Source: A lifetime of experience with funky accents in my name, not living in the place where the name comes from.
Source: A lifetime of experience with funky accents in my name, not living in the place where the name comes from.
You have to replace Ä with AE, Ö with OE, Ü with UE.
You won’t find a person named Müller under Muller in any database, especially not digital databases.
For electronic forms, always use äöüß, or, if the system happens to be an American one (the only form I’ve ever had to fill where I couldn’t use äöüß was a US DoD export declaration), use ae oe ue ss. Although be aware that some US software will have an issue with that, too, and just remove ß and assume äöü to be aou.
Asian passports seem to include something like this.
The only problem is that often there isn't a good clearly unambiguous set of rules on how to do that. For the forms, it doesn't matter, so long as the country chooses one and sticks with it. But it can mess up the pronunciation of your name real bad.