Can someone add a hyphen or a word to my domain name?

What does a hyphen or added word look like?

They must start with a letter, end with a letter or digit, and have as interior characters only letters, digits, and hyphen.

The real name stays whole and something is added around it: yourfirm-law.example, yourfirmgroup.example, yourfirm-invoices.example, or secure-yourfirm.example.

Words like billing, secure, pay or group read like a department or a new service, so the name looks planned rather than copied.

Why is an added word easy to miss?

That is, two names with the same spelling but different case are to be treated as if identical.

The same standard says two names with the same spelling but different case are treated as identical. So capital letters never make a new name, but a hyphen or an extra word always does, and the new name has its own owner.

Because your real name sits inside it, a reader who checks for your name finds it and stops checking.

What can I do about added words?

1. Decide which words a client might expect next to your name, such as your line of work or your city.
2. Check whether your name with those words, with and without a hyphen, is registered.
3. Register the most likely ones yourself and redirect them to your real site.
4. Tell clients the one domain your email and invoices come from.