pay together or separet
pagar en conjunto o separeto
2 Answers
I had to face this issue during the time I was on holiday in Spain this October and was wanting to pay for a meal in a restuarant in Las Ramblas in Barcelona.
On the first occasion I had arrived with one friend and had left it too late to do this as was explained by the waiter in question and another young gentleman after him who I think was the manager or owner of ''Café Brasil''.
On my second visit I was wiser and used the expression that the same waiter had given me as soon as I was seated at the table with others except I used it on behalf of others Nos gustaríamos pagar aparte(I was not sure how they said separately. the rest I knew well)
Me gustaría pagar ''aparte'' = I would like to pay separately (Polite version)
Quiero pagar aparte = I wish to pay separately (simple version)
I don't think that you need to ask to pay together in Spanish speaking countries since that is the expected/usual way to pay for group meals.
There will of course be other ways to express this same idea but as I was speaking Spanish and able to converse comfortably in other respects I know this to be a valid way of saying this.
I hope this helps 
.... is this a question? by the way you spelled seperate wrong. 
