Company ask to complete w9 for previous year ?

A company that I did some work for and I earned more than 600$ is asking me to fill out a w9 for 2017 in order to receive a 1099 ( the request to fill out the w9 has been made after January 31 2018 which is the deadline to receive a 1099)

I already filed taxes for 2017 and I reported the income as 1099 misc.


The company never asked a w9 when I started the contract work. 

Do i have to fill out that form or can i ignore it ?