They must have caused some confusion for your customers Roger.
Well, there's Cleaning Doctor franchise, there's Carpet Doctor franchise and I've seen advertised a cleaning product called Doctor Carpet.
I've got legal ownership of the limited company, the trading name and ".co.uk" domain name. I've also spoken to a solicitor whose an expert in trade name legislation and he said that "passing off" as it's known is difficult to prove. But yes I am aware of passing -off and what measures can be taken if necessary.
To answer your question directly some clients have mentioned the confusion but it's usually resolved itself. Those few people who have used one of the other companies when they had actually meant me find that the customer service/job quality control wasn't the same and then they realised their mistake and come back to me.
Having said that those who wanted me, went to the other companies and then never came back to me, well.........
It basically comes down to building brand awareness/corporate identity
How do you guys build your brand awareness? Do you think you've got a strong brand, a strong brand name and how do you promote it?