Birthday cards are the most frequently sent of all greeting cards. After all, everyone has a birthday —and most of us love to have our birthdays acknowledged by family, friends, co-workers, and other people in our lives. You probably can't buy a gift for every birthday celebrant you know, but cards are always a welcome way to recognise someone's birthday. Fortunately, Hallmark offers birthday cards for almost every type of recipient you can imagine, from long-lost friends to new family members, from co-workers to clergy, from newborns to 100-year-olds —and even cards from the family pet. So you can be sure that you'll find the right birthday card no matter who you're sending it to —and that they'll be delighted that you remembered their special day. To make birthday cards even more memorable, try a few of these simple tips from Hallmark's greeting card experts.

For family and friends
Personalise your cards with a little note, and always sign the card!
Keep your signature informal — no courtesy titles and no last names.
Traditionally, family signatures begin with the father's name, then the mother's and finally the children, or simply John, Mary and family.
If a card is from more than one person, the person who signs it should write his or her name last.
When sending a card to a couple with two different last names, address the card to Mary Smith and John Jones.

For business/work relationships
Mail cards for business associates to the office, or hand-deliver them. However, if you have a social relationship that goes beyond the workplace, it's more appropriate to send cards to the home.

Business greeting cards should be more tailored and formal.

Sign only your name to a card for a business associate unless your spouse has met the recipient.

Humorous cards are often well-suited to co-worker's birthdays; you may want to use more discretion before sending humorous cards to supervisors or managers

Special situations
Avoid sending religious-themed cards unless you're sure of the recipient's beliefs.

Take special care when sending a birthday card to someone who has recently been bereaved. A simple, thoughtful birthday wish will let the recipient know you're thinking of them, even if they're not in a celebratory mood.

Be sensitive when sending age-themed cards. Not everyone ages gracefully, and those who don't may not want to be reminded that they're getting older!