Beyonce Knowles' family and friends have sent handwritten messages for her birthday.

The 'Halo' singer turns 31 today (04.09.12), and many of those close to her have signed a special card which has been published on her website.

Her mother, Tina Knowles, wrote: ''God blessed me with one of the greatest gifts in my life on Sept. 4, 1981. Happy birthday.''

Beyonce's celebrity pal, Gwyneth Paltrow, also sent a message from her and husband Chris Martin, co-signed by their children Apple, eight and Moses, six.

She wrote: ''For dear sweet BB on the occasion of her 31st birthday... We love you so very much. Love Gwyneth, Chris, Apple, Moses (sic).''

Beyonce's younger sister, Solange, also paid tribute, writing: ''There is no-one like you in the world, of all of your mind blowing achievements that one that first comes to mind is your kindness.

''Your sense of selflessness, consideration of other people's well being and your beautiful generosity are all things that make me so proud be your sister and your friend.''

The 'Run the World (Girls)' hitmaker's former Destiny's Child bandmate, Michelle Williams, also sent well wishes.

She said: ''Happy birthday to youuu!! I love you so very much. I am so thankful you're in my life (sic).''

One of the most tender messages in the card was from Gloria Carter, mother of her husband, Jay-Z.

She wrote: ''B, You came into my life a sweet Southern girl. (LOL) You've blossomed into an amazing woman. I admire how you remain grounded and humble, and you haven't let success change the person that you are. Mama Carter (sic).''

Beyonce named her last album '4' and has previously discussed why it holds significance for her.

She said: ''We all have special numbers in our lives, and 4 is that for me. It's the day I was born. My mother's birthday, and a lot of my friends' birthdays, are on the fourth; April 4 is also my wedding date.''