I bought a house recently. The furnace takes a 16 x 22 filter. Turns out these are nearly impossible to find. Is it OK to use a 16 x 25 filter with 3 inches sticking out? The filter slides in the cold air return at the bottom of the furnace. I don't see where this would cause a problem, but just wanted to make sure.

It will work.

Yep, you'll be just fine.

As long as you are filtering the air going inside the furnace, that's all that matters.

Thanks everyone for the feedback. I figured it was okay but wanted to be sure. Thanks again!