Sizing issue

I’m working on a banner design for someone and they want it to be 20 by 3 feet which is 240 by 36 inches. InDesign has a limit till 216 inches so I can’t do the measurements I need. Is there a solution to this?
Or should I tell them that size can’t be done and they should give me new measurements?

what if you try doing it in AI?

It gives me this error message

I don’t know if it’s the correct thing to do, but I would make the canvas smaller but to the same ratio as the correct size

I was going to say what @malky-h said. But check to make sure the printer will be able to scale it up to size

First of all i just tried to create a document that size in Indesign CC and Illustrator CC and it worked fine. So maybe contact adobe support.

Secondly, i believe it’s standard practice for very large banners to be scaled down proportionally and even a lower resolution. If you make a 300dpi huge file the printer may not even want to handle something like that. When you look at a billboard close-up you normally see it is very pixelated b/c it’s not done in 300ppi b/c it’s not meant to be viewed close up. So also a big q for your client is to find out how far people will be viewing the banner.

Hatzlacha!