In the next step of an advocacy campaign to make it easier for families to apply to charter schools, 20 schools have teamed up to put a common application online.

The application, which was developed by the city’s main charter advocacy organization and is available through its website, allows parents to apply to multiple charter schools by filling out a single online form.

By introducing the online common application, charter advocates hope to increase demand for charters. They’re also trying to answer critics’ charge that the overwhelming and duplicative paperwork that marks the current admissions system discourages all but the most motivated parents and effectively screens out needy students.

Last year, the city introduced a paper common application, which parents could fill out and submit to any of the city’s roughly 100 charter schools.

The schools participating in the pilot are: