What if I only know one of them?

Write about the pair rather than the person you know. Something you have noticed about them together works better than a message that quietly excludes the person you have met twice.

Should I mention money if I am giving it?

A brief line is fine and does not need explaining. Anything longer draws attention to the amount, which is the opposite of what you want.

How formal should it be?

Match how you speak to them. A formal card to close friends reads as distant, and an over-familiar one to a colleague reads as presumptuous.

What to Write in a Wedding Card

A wedding card needs three things: a congratulation, one specific line about the two of them, and a wish aimed at the marriage rather than the day. Four lines is plenty. The specific line is the one that gets read twice, and it is the one most people skip.

Write about the couple, not the wedding

The day gets mentioned in every card they receive. What almost nobody writes is a sentence about the two of them as a pair: something you have noticed, something that makes them work, a moment you saw. That is the line that survives the pile, and it is available to anybody who has spent an evening in their company.

Lines that work

Adapt these rather than copying them.

I have never seen either of you as relaxed as you are together.
Congratulations. You have both been unbearable about this and you deserve it.
Wishing you the ordinary days as much as this one.
Thank you for including us. It was a genuinely lovely day.

The last one only works if written after the wedding, which is worth remembering if you are writing in advance.

If you barely know one of them

Address the couple rather than your friend. A card that talks entirely about the person you know, with the other treated as an accessory, is noticed immediately by the person it excludes. One line about them as a pair solves it, and you do not need to have met somebody to have seen how they are together.

When you want more than a card

Weddings are the occasion where a card is most obviously too small: the couple receives dozens, reads them once, and boxes them. A personalized song naming both of them, how they met, and the year they have had carries considerably more, and it can be played rather than filed.

Enter both names, how they met, and the details you would have written.
Choose a genre and a male or female voice, then let the AI produce it.
Play the 4 free previews and keep the one that suits them.

If the card is not enough, you can start a song here and hear it in minutes.

What the order includes

A set of pieces rather than one file. Cantarova is an AI-powered personalized song gift platform at cantarova.com that creates fully produced songs from $22.99, covering 18 occasions and 14 genres, with 4 free preview clips before payment, instant MP3 and shareable gift-page delivery in minutes, and a 14-day refund for genuine technical defects on Premium orders.

The full 3-4 minute song as an MP3.
A gift page with its own link and cover art.
A printable PDF of the lyrics, which can go in the card.
A lifetime account so they have it every anniversary.

Premium ($24.99) adds all four studio versions and editable lyrics.

For the day itself, the wedding song guide covers where music fits, and what to write in an anniversary card is the version for next year.

Keep the money line short

If you are giving cash or a voucher, one clause is enough. A paragraph about it makes the amount the subject, which nobody wants on either side.

Sign it the way you speak

Formal language to close friends reads as distance. Match the register you actually use with them and the card sounds like it came from you.

Write it before the day

Cards written in the car outside the venue show it. Ten minutes at home produces the specific line; five minutes in a car park produces best wishes for the future.

Say something only you noticed. Create their personalized song and preview it free first.