With a UK passport he should be able to get one on arrival, one thing though you will need a credit card, you cant pay it with cash. You can buy a like an ecash card which you top up and then use to pay for government services.

You can apply for one online in advance you may be able to do it today on the gov website.

http://www.gov.qa/wps/portal?New_WCM_Context=/wps/wcm/connect/cnt/en/1_h...