What does a city need to do in order to become a capital city?

The selection of a city to be a capital is one that is made (and, in almost all cases, has already been made) by a higher level of government. It is, after all, the higher level of government that is responsible for the capital itself, i.e., the place where the government's functions are carried on. As indicated, the selection of a capital is one that, for the most part, has already been made. In many cases, the decision was made a hundred years ago, and often more. For a city to convince the higher level of government to uproot itself and move elsewhere would certainly take some doing. The first question to be asked is, "Why move at all?" If the decision is made to move, the next question is, "Where?" You can bet your bottom dollar that several other cities will be in the running. Moving a capital would be an extremely expensive proposition. How and why should the taxpayer be expected to pay for it? These are just a few of the preliminary issues that would have to be faced.