555-1212 is directory assistance generally. There are a few other 555-xxxx numbers allocated, too. Another trick is to use a 1 in the first nxx, so npa-1xx-xxx

555-1212 is directory assistance generally. There are a few other 555-xxxx numbers allocated, too. Another trick is to use a 1 in the first nxx, so npa-1xx-xxxx. Downside is that some basic US telephone checks/regex might fail it.