In the United States, 40 of the 50 states require charitable solicitation registration in some form or another.
There is no standard form to fill out, so if you plan on asking for donations in a state, you have to submit your paperwork with that state.
Many states will, however, take the Unified Registration Statement, although they often require additional paperwork, forms, and sometimes a nonprofit’s IRS form 990.
If you know you’re going to be actively asking for donations in a particular state (where your nonprofit is based, for instance), you should definitely register with that state.
Additionally, if you have an online donation form, your donors could donate from any state; it’s wise to register with every state to avoid fines and penalties for soliciting donors in a state in which you aren’t registered.