Generally, where common law or informal marriage is recognized at all, it requires both shared intent to marry and publicly presenting as married. I know I’ve seen fiction where it requires little more than cohabitation, but that’s not a real thing.
Revenue Canada has their own definition of common law, for tax purposes only (not litigation), which is independant of that and is 12 months.
New Hampshire: Common Law Marriage: "persons cohabiting and acknowledging each other as husband and wife, and generally reputed to be such, for the period of 3 years, and until the decease of one of them, shall thereafter be deemed to have been legally married." (N.H. Stat. §457:39)
So not really a fiction. There aren't many requirements there.
The old law in PA did not even require habitation or a contract. All that would be required aside from regular eligibility stuff would be presenting themselves in public as husband and wife plus exchanging words of intent at one time to be married (verbal contract). That law was active until as recently as 2005.
Your recent PA law is in accord with my point that the rules usually require mutual intent to marry plus public presentation.
Emphasis mine. Merely stating you're husband and wife is "little more" in my book. It's pretty easy for people to think you're married, especially if you tell people you're husband and wife to make the conversation easier.
Can’t really understand doubling down on claiming it is relevant after having the relevant issue pointed out again, but, you know, you do you.