Is it bad practice?

[CleaningServices]

I set up this small cleaning business 6 months ago and thought I would be lucky to get a few regular customers, but it has ballooned and I now I have 3 businesses, 2 holiday homes and 6 weekly customers on my books which is fantastic and better than I expected, but my dilemma is can I now go back to the businesses that I have had from the start and ask them to sign a contract (1 in particular who is being a bit arsey)?
I didn't ever think I would be in a position to even have a contract but I feel to protect myself and the customers and so we both know exactly where we stand it's maybe best to have one, how would you go about it, anyone been in a similar position? Is it bad practice?

Dear Customer,

I've been tidying up my paperwork for my insurance renewal and to ensure that both of us are properly protected in the services we receive / provide, could you confirm the attached contract and send one copy back to me.

If you have any queries, please feel free to drop me a line and see you on &&& date for my next planned visit.

Cheers
CS

It is not bad practice to "tidy" up loose ends from the beginning of your relationship with your customers.
It is not an easy conversation to have but it must be done.
A lesson for others who may read your post.
Good luck

Thank you both for your input, its very helpful, you are right Gfplux, a lesson for others indeed x