Since this is quite the birthday milestone, it makes sense to send the lucky boy or girl a beautiful custom 18^th birthday card and message to match. Below are some ideas to inspire a joyous, celebratory mood in both you and the birthday card recipient, whether your intention is sentimental, light-hearted or playful.

Birthday messages to write in an 18^th birthday card as a parent

• Nothing comes close to the joy of being able to make your own decisions – just like how nothing comes close to the burden of being responsible for them. Happy 18^th birthday.
• No matter how old you become, our arms are always open for a warm hug. Happy 18^th birthday son/daughter!
• Turning eighteen is about enjoying freedom on one hand and fulfilling responsibility on the other. I hope you can strike the perfect balance in doing both. Happy 18^th birthday.
• It does not matter whether you are eighteen or eighty one, you will always be daddy’s little girl. Happy birthday.
• Turning 18 means that you are in-charge of your destiny, but don’t forget that with freedom, comes responsibility. Happy birthday.
• Congratulations on finally becoming an adult. Maybe you want to start behaving like one too? Happy 18^th birthday.
• Make the most of your eighteenth while you can. Life is going to fly past and in no time you’ll be old like me. Happy 18^th birthday!
• Cherish your friendships, never break someone’s heart. Remember your parents, who have supported you from the start. Happy 18^th birthday
• As your parents all we want to say is that we are really proud of the way you have grow into a fine young woman. Keep going, keep reaching new heights – just remember that you my dear, are special to none. Happy 18^th birthday.
• Eighteen is the age when you can do whatever you want, but at one condition – you pay for it. Happy 18^th birthday.
• Laugh as hard as you can, smile more often. Share your joys, spread happiness by the ton. Be wise but be carefree, don’t let small issues make you fret. You are 18 only once… Happy birthday!
• Never be afraid of failure. It’s how we eventually succeed. Happy 18^th, my love!
• We’re so proud of everything you are and everything you’re going to be. Happy 18^th son/daughter!

What to write in a friend’s 18^th birthday card

• Best friends since birth. Eighteen years together and I hope for at least another eighteen more.
• Through this new adventure of adulthood, you’ll always find me beside you. Happy birthday, friend.
• I couldn’t imagine growing up with a better friend. Good times or bad, you’re always there. Wishing you a beautiful day and happy eighteenth!
• Happy 18^th birthday to the most wonderful friend of mine. Always keep smiling because it suits you the most. Best wishes to you!
• Happy 18^th birthday! Today, my advice for you is simple: live each day of your life like it’s your birthday. Celebrate what makes you, you.
• Happy birthday to the best friend a girl could ever ask for. Thanks for listening to me when I need an ear or making me smile when I am down. May you have all your wishes come true today.
• The pictures of my childhood would have been incomplete if they didn’t have a beautiful face like yours. Happy birthday to the coolest eighteen-year-old in the school.
• From now on when a website asks if you’re 18+, you won’t have to lie anymore. Have a wonderful birthday, mate!
• You are the reason my life experiences spring and summer. Without you, my life would have been totally boring. Happy 18^th birthday to my bestie!

How to send your sibling happy 18^th birthday wishes

• Enjoy life to the fullest, but wisely. Go grab what’s in your destiny. Happy 18^th birthday!
• Life begins at 18 – enjoy it. Happy birthday!
• Happy 18^th birthday! Although the world considers you an adult, you can continue being the idiot kid in front of me.
• Here is to 18 incredible years of your amazing life dear sis. Enjoy the fabulous 18 birthday with lots of joy and warmth.
• A number of new experiences, new achievements and new friends are on the way for you as you celebrate your 18th birthday. Best wishes for you!
• You are pretty and fabulous and elegant eighteen today but deep down you know that I am our parent’s favourite child. Still Happy Birthday.
• 18 comes with fun, recklessness and responsibilities. I know you will deal it with better than anyone else. Happy Birthday, sis!
• You have a journey to be experienced, and a mission to be the greatest of all the greats. Let’s start it all from today. Happy 18th birthday!
• Best wishes to you on this special day of your life. May you always be happy and successful! Happy 18^th birthday, brother!
• Old enough to make your own decisions and young enough for every adventure, you’re at the best stage of life. Happy birthday!
• The journey of youth has suddenly become a journey of adulthood. Don’t be afraid of this new world because you’re going to have a great experience
• Stop Aging. No, seriously, stop aging. You’re a perfect age right now. It doesn’t get any better than 18.

18^th birthday message ideas for your boyfriend/girlfriend

• Happy Birthday to the most amazing 18 year old I know. This is your time. Live life to the fullest. Love you!
• Happy birthday to the best boyfriend in the world. I wanted to plan a surprise party. But we know I cannot keep a secret.
• I am sending you an ocean of love. I hope your birthday is as cool as you are. Enjoy the day, and put your happy face on.
• You always hold my hand gently. You always listen to me, day and night. And you make everything right. Happy Birthday, my love. Thanks for being my boyfriend.
• You are a lot like the sun. You give unlimited happiness to everyone around you. And you give us inspiration and put a smile on our face. Happy birthday to my special sun, my charming boyfriend.
• May this new phase of your life bring about positive vibes, new possibilities and new adventures. Happy birthday to you, beautiful girlfriend.
• I’m so glad to see you turning eighteen on this special day. I wish you long life and prosperity, and may all you desire come true. Happy birthday, babe.

View all birthday greeting cards designs on Snapfish, and read our greatest and latest birthday card designs article on the blog to help you create the best 18^th birthday card ever!

Snapfish + Macmillan are working in partnership to raise vital funds. For every greeting card or flat card set sold, Macmillan receive up to 15p.

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