I have 2 review letters requiring the IRS Account Transcript. These are my first ones that require the transcript.
How long does it take to get them?
If the client has an online IRS account they can log in and retrieve the transcript immediately.
Otherwise, I believe they come fairly quickly (under 2 weeks) if they are mailed to the client. If going the mail route, you should be able to use this link to make the request.
Via snail mail it doesnt take long at all. Usually a couple of weeks.