If you want to get a national identity card from the government,
it's highly likely you'll need to do so by completing a form,
rather than writing a letter. Find out from them what form you need
to fill out, and any documents you may need to submit with the
form, as well as whether there is a processing fee. You can find
this information by searching your government's web site, phoning
your local authority, or writing a letter to them. If you write a
letter to them, don't forget to include your own address in the
letter.