Dick Frame is an agent with MI5.
That is my guess. I know in the second recorded adventure he is identified as being with that organization but whether it is also true in the first, I couldn't tell you. Frame could have, of course, but instead of actually stating his employer's identity, he referred to such matters as "Russian House" and "Crazy House" and "the Firm" and since the action takes place in the early 1970's, I am at a loss.
Still, MI5 is my first, best guess. Whatever it was, though, he had been with it for around six months when we first meet him and, according to his wife, Jeannie, was still only part way through his promised training period when he gets a call to his first mission. She indicated that he was not likely ready and her assessment holds up considering the very nasty things that happen to him on it.
That first mission is where he will meet Charley Panarti, a fellow field agent and someone he took an immediate dislike to at their first introduction but who would quickly turn into Frame's best friend and partner and someone Frame could rely on to have his back just as Frame would have Panarti's. You would never think that, of course, if you listened to practically any conversation between the two - words of kindness are cleverly hidden in sentences of scorn.
From the very beginning of his official career, not counting the one fourth of the training he was promised before his first mission, the official description of his efforts have been, according to his bosses, "a catalogue of disasters". As one of his superiors put it, "The only reason I have not recommended your removal from the firm - and you can take that whichever way you like - is that I need someone to blame when the s**t hits the proverbial - simple as that." That sounds pretty harsh but considering the way that everyone seemed to talk to everyone else, it was not too bad. And despite the insulting words, the powers that be still called upon Frame and Panarti because somehow they got the job done.