Birthday Wishes for a Sister-in-Law or Brother-in-Law: 45+ Messages

In-laws you actually like are one of the underrated pleasures of getting married. Here are 45+ messages for a sister-in-law or brother-in-law’s birthday.

Send yours in a free birthday ecard.

Quick birthday wishes

1. Happy birthday! Have a brilliant day.
2. Happy birthday! Hope you get thoroughly spoiled.
3. Wishing you a very happy birthday.
4. Happy birthday from us both. Enjoy it.
5. Many happy returns! Have a great one.
6. Happy birthday! Lots of love from all of us.
7. Wishing you a wonderful birthday.
8. Happy birthday! Hope the day is a good one.
9. Have a fantastic birthday!
10. Happy birthday! Looking forward to celebrating.
11. Happy birthday — enjoy every minute.
12. Happy birthday! Wishing you a brilliant year.

Warm messages

1. Happy birthday! Genuinely glad you married into this family.
2. Happy birthday. You have made my brother far more bearable. Thank you.
3. Happy birthday! Gaining a sister was the unexpected bonus of that wedding.
4. Happy birthday. Thank you for how happy you make her.
5. Happy birthday! You fitted into this family instantly and we all noticed.
6. Happy birthday. Lucky to have you as a sister-in-law and luckier as a friend.
7. Happy birthday! Thank you for being such a good parent to our nieces.
8. Happy birthday. This family is better with you in it.
9. Happy birthday! Very glad we ended up related.
10. Happy birthday. Grateful you came with the package.

When you are properly close

1. Happy birthday! In-law on paper, actual friend in practice.
2. Happy birthday. You are the one I message when this family is being ridiculous.
3. Happy birthday! Best thing my brother ever did was marry you.
4. Happy birthday. Our alliance at family gatherings remains undefeated.
5. Happy birthday! Sister-in-law is not the right word at this point.
6. Happy birthday. Thank you for always taking my side.
7. Happy birthday! Stuck with each other now, and glad about it.
8. Happy birthday. Genuinely one of my favourite people.

When it is more of an acquaintance

1. Happy birthday. Wishing you a lovely day and a good year ahead.
2. Happy birthday! Hope you have a wonderful celebration.
3. Wishing you health and happiness in the year to come.
4. Happy birthday! Thank you for everything you do for the family.
5. Happy birthday. With warm wishes from us both.
6. Wishing you a peaceful and happy birthday.
7. Happy birthday! Hope the day is exactly as you like it.
8. Happy birthday, with best wishes for the year ahead.

Short messages

1. Happy birthday!
2. Have a wonderful day.
3. Happy birthday from us both.
4. Many happy returns!
5. Have a great one!
6. Happy birthday — enjoy it!
7. Lots of love on your birthday.
8. Wishing you a lovely day.

How to write it

1. Say something about them, not their spouse. In-laws are frequently addressed only as somebody’s partner.
2. Match your actual closeness. Warm and brief is never wrong; overclaimed intimacy is awkward.
3. Mention them as a parent if they are one. It usually lands better than praise about the marriage.
4. Sign from both of you. A joint card is the norm and avoids any suggestion one of you forgot.

Send it — and pair it with a gift

A free birthday ecard arrives on the day. See also birthday wishes for your sister and birthday wishes for your brother:

FAQ

What do you write in a birthday card for a sister-in-law or brother-in-law?

Say something about them personally rather than about their marriage. In-laws are too often addressed only as someone’s spouse.

What if you are not close?

Keep it warm and brief. “Happy birthday! Have a brilliant day” is entirely sufficient.

Can it be funny?

Yes if you get on. Teasing about the sibling you both have to deal with usually lands well.

Should you call them family?

If it is true, say so. Being explicitly counted as family is something in-laws often say they wanted to hear.

What is a good short message?

“Happy birthday! Have a brilliant day.”

Should the card come from both of you?

Yes, signing jointly is the norm.