Working with a friend. No agency

[#1]

I read posts here but didn't found the right answer.

I'm web developer. But often I saw job like "Web design and developer needed". I see no sence make agency for this. Is it good for your system if I (and sometimes he) write something like this: "I'm developer, but my friend is designer. We can work together (he have his own UpWork account) if you agree." So, he work in his own account and me too but in one project. Do we break rules?

Thank you.

[#2 · Accepted solution]

Hi Roman,

While there isn't an option for more than one person to be hired on the same contract, you and your friend can be hired by the same client on two different contracts and you can still collaborate and communicate in Messages. 
Alternatively, you and your clients can also discuss an option of subcontracting which is allowed but only on fixed-price contracts.