Holiday cards, particularly Christmas cards, are big business. Leading greeting-card maker Hallmark estimates 1.3 billion Christmas cards are sent annually in the United States.

Every holiday season, I receive a handful of cards addressed to “Mr. and Mrs. Mark Peacock” — my husband’s name. And every year I’m flummoxed that some in our circle haven’t noticed that Mark and I have never shared a last name.

Etiquette is based on historical precedent, but also follows cultural shifts, of which there have been many in recent decades. In other words, “Mr. and Mrs. Husband’s Name” doesn’t cut it anymore for a lot of people.

“To address people that way is pretty outdated,” says Arden Clise, who owns Seattle-based Clise Etiquette and wrote the book “Spinach in Your Boss’s Teeth: Essential Etiquette for Professional Success” (Silver Fern, 2016). Nowadays, Clise said, many women have also disavowed the title Mrs. for Ms., which does not spotlight one’s marital status.

If you don’t know, ask

Experts agree that the first step in addressing holiday cards is to know your recipients’ preferences.

Are they married with separate or hyphenated names? Was a new, blended name created? Do their children have different surnames?

“If you ever have a question, just send the person a text or email and ask,” says Jodi R.R. Smith, owner of Mannersmith Etiquette Consulting in Marblehead, Mass. “You should know if a name is hyphenated, and which name comes first, which comes second.”

You can use a less formal approach by writing one family member’s last name, usually the person you know best, and addressing the card to the “family”: “The Jones family,” for instance, or “Ralph Jones and family.”

A new courtesy title, Mx. (pronounced “Mix”), has been embraced by some transgender, nonbinary or gender-neutral people as an alternative to Mr. or Ms. It was added to the Oxford English Dictionary in 2015, but the etiquette is evolving, and Smith recommends tailoring “Mx.” to the recipient’s preference.

“I actually recommend contacting them individually and asking how they prefer to be addressed formally,” she says.

Traditionally, the man’s name came first in addressing a married couple, but now the opposite is proper, Smith says. Address a card with the woman’s name first. And for any married couple, she says, etiquette requires an “and” between the two names.

Cut senders some slack

There are lots of new rules; understand when it is and isn’t appropriate to be an etiquette cop.

“Don’t bother trying to change your elderly relative,” Smith says. “But if your cousin doesn’t know your name, send him a gentle email after the holidays are over and suggest he make the change in his master list.” Close the email with a positive note or two, she says, something like “Can’t wait to see you at the family reunion next fall!”

And don’t let address worries scare you off from sending these annual greetings. People love getting cards in the mail.