Happened to my last company, the new company didn't want to budge and it must have cost £20k to rectify compared to the few hundred it would have cost if we'd registered it ourselves when we started trading 10 years earlier.
Proving we'd got unregistered rights to the mark was possible because of our marketing and lots of nice letters from customers. But it was perfectly possible that we could have lost it.
You know where your customers are - register there, and early!
> Happened to my last company, the new company didn't want to budge and it must have cost £20k to rectify compared to the few hundred it would have cost if we'd registered it ourselves when we started trading 10 years earlier.
£20k might be cheap compared to the fees associated with keeping a TM registered in multiple categories in multiple countries for 10 years.
It's pretty easy to spend $5K registering a TM in two countries across the number of categories you'd expect most SAAS companies to register in, and generally I think that gives 5 years of protection.
It's a tricky expense to justify when you're bootstrapping, but if you're funded at all - put those TM registrations on the list!
If you start doing business is a country using a name it (usually - depending on local laws) provides some protection against others registering that trademark in that name (as a non-registered trademark).
You need documentary evidence you were using it in that country before the trademark was attempted.
You can then spend the money to register a trademark at some future time.
But talk to a (good, IP specialist) lawyer! Even $5-$10K on lawyer fees is cheap compared to registering international trademarks in multiple categories.