Hi all, I think i may have made a mistake with my guest list and wondering if of you kind people can help me?

On my guest list there are some people who have no partners and some people who have partners that we dont know. So my question is for example if i had a cousin say that had a partner and i didnt know their name, I would prob put Jack and partner on the invite right?
However what happens if someone does not have a partner? do i either put mr x and partner down and double our numbers our do we just put mr x? me and h2b were looking at this last night, and knowing full well they dont have a partner and wouldnt bring anyone im not paying another 3 course meal for someone who does not exist!!
So im thinking if they have a partner then mr x and partner but if they dont imjust gonna put mr x. what do you think? do you think this is rude I feel this is the fairest way as if you put a partner with everyone that would double numbers if that makes sense??

Please help :)