Only if the plumbing company is not a corporation. If its not obvious (i.e. You don't see Inc. in the name), give the company a W9.
https://www.irs.gov/pub/irs-pdf/fw9.pdf
In general, at the time when you pay or contract to pay, you should always present W9 forms to contractors. If they are incorporated, the company attests to this on the W9.
A sole proprietor, LLC, "Joe", etc. all get 1099MISCs.
