My employer doesn't have an iPhone for testing, they are also not enrolled into Apple's developer program, but they recruited me as an iOS developer.
I was told to create an app and I did it with the help of simulator.
Now, they want me to generate an IPA file of that application for their client who is in another country to test, in his iPhone. Is that even possible?
You will certainly need a developer account if you want to run your app on a physical device (unless that device is jailbroken, which I wouldn't recommend). If your employer hired you as an iOS developer, you need to inform them that a requirement to doing iOS development is a developer account.
If you are going to be writing iOS apps to deploy on client device (which you won't have physical access to), you have a couple of options.
Bottom line, if your company is asking you to develop apps professionally, you need to get them to understand that the $99/year fee is part of the process. IF they can't justify that, they shouldn't be hiring out iOS development jobs.