Ever wondered why some birthdays are considered milestones?

The term milestone dates back to the Ancient Romans. When they created the first-ever system of roads, they would use a stone obelisk to mark 1000 paces or one mile. Nowadays, it is perceived as a measurement of time as well as distance. For example, getting your college degree, buying a house, or getting married are all considered milestones in life. Whether it’s your 18th, 21st or 70th, we also see certain birthdays as milestones. This is often a time that we reflect on where our life is going and the experience that we have already had. 

Looking for inspiration on what to write in a milestone birthday card? Check out this array of specific messages that are ideal for your loved one’s milestone age celebration.

For general birthdays (non-milestone), take a look at this article for tons of ideas on what to write.

These once-in-a-lifetime birthdays only come around once, so make it extra special by sending a real birthday card in the post! With 70,000+ personalizable designs, you can create the perfect card yourself. And if you’re short on time, we even have a range of (free) pre-written messages you can choose and edit accordingly.

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Things to write on a birthday card

Things to write on a birthday card include:

  • The birthday girl or boy’s name (or nickname!)
  • Their milestone age
  • Your birthday wishes for them
  • A loving sign off

The 4 best birthday messages for any milestone age:

  1. Happy **th birthday! Did you know birthdays are good for the health? The more you have, the longer you live!
  2. However old you get, just remember one thing, I’ll always be older!
  3. Happy **th birthday! ** are the new 20s!
  4. Congratulations on being on this Earth for ** decades!

There’s a lot to think about when wishing someone a happy birthday. Luckily though, writing a card for a milestone birthday can be a little more specific to the landmark occasion, with messages such as.

What to write on a 1st Birthday card

A small child opens his birthday present and milestone card on his first birthday

Although they may not be able to read the message just yet, this card will hopefully be the first of many. If you are looking to write an extra special 1st birthday message, you could write something like:

  • Happy birthday to you! We hope that you have enjoyed your first year on the plant as much as we have enjoyed having you here!
  • The first of many to come, although it is one we do not remember our 1st birthday party is certainly something to celebrate.
  • I wish you all the happiness in the world on your very first birthday!

Writing a 13th Birthday Card

As your child turns into a teenager, this special birthday is often a big celebration. If you are wondering what to write on a 13th birthday card for boy or girl, you could consider something like:

  • Congratulations on officially becoming a teenager- you are still the youngest teen I know!
  • Your seven years as an official teen start now – use them wisely!
An example text of what to write in a 13th birthday card
  • May all your birthday wishes come true as you reach your thirteenth!

Sweet 16th Birthday Messages

A girl sits ready to blow out her candles on her birthday cake

A person’s sweet sixteenth is often one of those birthdays that they remember for years to come.  Sweet sixteenth birthday wishes could include:

  • Happy sweet 16th to the sweetest person I know!
  • We couldn’t be prouder of the person you have become.
  • As we celebrate your sweet 16th, I hope that all your dreams and wishes come true.

What to Write for an 18th Birthday Card

Considered to be the gateway to becoming an adult, the 18th is seen as the most important milestone birthday in many countries. A birthday message for an 18th could be:

  • Welcome to adulthood! Happy Birthday!
  • Here is a list of 18 reasons why you are the best person I know…
  • I hope your 18th birthday is everything that you wish for!
  • As your journey of life truly begins, I hope that your future is as bright as you are!
  • Hope you have a wonderful day as we celebrate your transition from being an awesome kid to an awesome adult.

What to write in a 21st birthday card

A woman celebrates her 21st milestone birthday holding balloons

In the USA, this is when you can first enjoy a drink legally and enter casinos. However, this milestone celebration dates back to medieval times, when a man could become a knight at 21 years old.  When writing a 21st birthday card you could include phrases such as:

  • Take it from me: Just because you’re technically an adult doesn’t mean you have to grow up.
Funny birthday wishes for a 21st birthday card
  • Finally old enough to have a drink! Hope you have the happiest of birthdays!
  • I cannot believe you are classed as an adult now? In my mind, you are still the five-year-old cutie who always had a smile on his/her face.

Fabulous at 30 Birthday Messages

Traditionally a birthday when many people start to feel older, your 30th is seen as a major milestone birthday in adulthood. You could write a message such as:

  • You might have turned 30, but you can still party like you are in your 20s!
  • Like a fine wine, you have only got better with age. However, I think we might need a fire extinguisher handy with that many candles on your cake.
  • Congratulations on staying on the planet for three whole decades!
An example of what to write in a 30th milestone birthday card

40th, 50th and 60th Birthday Wishes

A woman holding balloons on a walk.

This golden birthday is the second most celebrated in adulthood and you could write something like:

  • Congratulations on reaching half a century!
  • Still fabulous at fifty. Hope you have a wonderful birthday.
  • Here’s to the next fifty years together- Happy Birthday!
  • I hope you have a wonderful 50th birthday and I can’t wait to spend your special day with you.
  • Wishing you a fun-filled fiftieth celebration!

What about 40 and 60?

For a lot of people these ages mark an important milestone. Here’s what you could say:

  • 40, flirty, fabulous. Love you, babe.
Forty, flirty, fabulous: Example birthday wishes for a 50th milestone birthday
  • 40 years old with the looks of someone half your age and the wisdom of someone double it!
  • The world is so lucky to have had you for 60 years and counting!
  • You may be 60 but you’ll always be my little sister/ brother!

 100th Birthday Messages

An old lady in front of her 100th birthday cake

A hundred is undoubtedly one of those special landmark ages, and some good messages to write in a birthday card could include:

  • As you have reached a century, I wish you all the joy and love you deserve on this magical day.
  • With a century’s worth of wisdom, a heart of gold and a sense of humour that would make a sailor blush, you are the best 100-year old I have ever known! (And the only one!)
What to write in a 100th birthday card sample text
  • I don’t know why people keep saying it’s your 100th! You don’t look a day over 21 to me!

Find your perfect milestone birthday message?

We hope that you have been inspired by our selection of example birthday greetings for milestone birthdays. Hopefully you have a better idea of what to write in a 1st birthday card or a 21st.

Celebrating from a distance? Make sure to check out these awesome ways to celebrate a long-distance birthday.

Or perhaps one of these articles is for you:


Hiya, I’m Maud. I’m an English girl who's moved to Berlin - because who wouldn’t fall in love with a country which has words like ‘Kummerspeck’ hidden around every corner... I love traveling and finding out the quirks of each country - and what better way to remember them than on a postcard?

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