Match specific length x or y

I'd like a regex that is either X or Y characters long. For example, match a string that is either 8 or 11 characters long. I have currently implemented this like so: ^([0-9]{8}|[0-9]{11})$.

I could also implement it as: ^[0-9]{8}([0-9]{3})?$

My question is: Can I have this regex without duplicating the [0-9] part (which is more complex than this simple \d example)?