Today I have been fired by the company I am working. Great way, to start the day Anyways, I am curious if I can ask the company to send an official dismissal letter in written form. I have heard it orally at the moment.

Any such information will and should be done/followed up with an official signed, dated and most likely stamped letter.

The dismissal is not official until you receive it in writing and countersigned it. This is what I was told by a previous boss when the company I was working for downsized. They made sure everyone had there letters and signed them before the end of the month when we were told it was going to happen.

That's not true.
A dismissal is official if it's oral and/or not countersigned but people just do it in paper form and countersign it, because you then can't go against it anymore.

One should insist on a dismissal in written form and I don't know any company who wouldn't do it, because it's the most sensible thing to do.

And you`d it in writing for the Jobless Dept. And I understand that it must be sent registered.