Ten ideas
Fill their birthday tree
Get them to make a birthday tree and share its link, then hang a gift with a message on it and ask their friends and family to do the same. Everything opens on their birthday.
A countdown on their phone
The birthday countdown widget shows the days to their birthday on their home screen (Android, with the app’s next update).
Be first at midnight
Call or text the moment their birthday starts in their time zone.
A video party
Gather their friends on one call and sing at the same time.
Cake to the door
Order a cake or their favourite food from a bakery near them.
Messages from everyone
Collect short notes from friends and family; their tree holds them all in one place.
Open gifts together
Post the gift early and watch them open it on camera.
A playlist of your songs
Put together the songs that remind you of each other.
A letter in the post
Handwritten and timed to arrive on the day.
Plan the next visit
The best present can be a date on the calendar.

More ideas: the best apps for long-distance couples and long-distance Valentine’s Day ideas.
Questions
How do you celebrate a birthday in a long-distance relationship?
Mix something live, like a video call at midnight their time, with something that waits for the day: messages on their birthday tree open on their birthday.
Can I make a birthday tree for my partner?
The tree belongs to the person whose birthday it is: they make it and read its messages. You fill it: open their link, pick a gift and write your message.
Do their friends need an account?
No. Anyone with the link can leave a gift with a message from any browser.
Is it free?
It’s freemium: making a tree, sharing it and sending messages are free; removing ads, putting your tree on the world map and other extras are paid.