Quick answer
Any card that names the baby, congratulates the parents, and arrives within a few weeks of the birth does the job. You don't need a poem or a paragraph. Short, warm, and signed by hand beats clever every time.
What to write inside
I keep it to three beats: congratulations to the parents, one line about the baby, and something personal or useful. That's the whole formula.
- Congratulations to you both. She's here and she's wonderful.
- Welcome, [Name]. The world just got better.
- So happy for your family. Can't wait to meet the little one.
- Congrats. Hope you're getting some sleep and a lot of takeout.
Use the baby's name if you know it. If the parents haven't shared one yet, "your little one" or "the newest member of your family" reads fine.
If you're close to them
Add a real detail: a memory of the parents before kids, a line about how their dog will handle the demotion, an offer with a date attached. "I'll drop dinner off Thursday" beats "let me know if you need anything," which quietly hands the work back to them.
If you're not close
Two sentences. Congratulations, warmth, your name. Skip jokes about sleepless nights if you don't know their sense of humor, and skip advice entirely.
Who signs it
Couples sign both names. At work, a small team can share one card with everyone signing, but if the group is large or spread out, write your own. When a group chips in on a gift, put the card with the gift and note who contributed so the parents know who to thank.
When to send it
Anywhere from the birth to about six weeks out feels right. After that, send it anyway. A card that shows up at three months, once the visitors stop and the fog is thicker, often gets more gratitude than one that landed in the first week.
If you find out late, don't open with an apology. Just congratulate them.
Cards for the less common cases
- Twins or more: one card, both names. Two separate cards can make it read like two separate events.
- Adoption: a standard new baby card works. Same message, same warmth.
- Grandparents, aunts, uncles: a small congratulations card is welcome, and grandparents tend to keep them.
- NICU or a hard start: follow the parents' lead. If they've announced the birth, congratulate them on the baby and leave the medical details alone.
Envelope and mailing notes
Write the parents' names on the front and, if you like, the baby's name on the back flap. Hand-addressing it takes two minutes. If you're mailing, a standard rectangle goes at the first-class rate; square envelopes and thick, rigid, or oddly shaped cards cost extra. Weigh one at the counter before you buy a sheet of stamps.
What to leave out
No questions about sleep, feeding, weight, or when they're having another. No medical advice. No "your life is over" jokes, even as a joke. A congratulations card is one small piece of good news in the mailbox. Keep it that way.