A gay marriage law approved in February by the Scottish Parliament has taken effect.

Gay and lesbian couples may begin applying for a marriage license, but a 15-day waiting period means the first weddings won't take place until December 31.

Couples in an existing civil partnership may immediately convert to a marriage.

According to the BBC, Douglas Pretsell, from Edinburgh, and Peter Gloster, from Melbourne (pictured), were the first couple to convert their civil partnership to a marriage. The couple upgraded their union at the British consulate in Sydney, hours before registrars in Scotland opened for business.

“It was kind of coincidental,” Pretsell said on BBC Radio's Good Morning Scotland. “We weren't originally intending to be the first at all.”

“We sent an email to the consulate asking how long after the weddings came in that we would be able to change our certificate. We got an email back from them, asking if we would be able to come in at 11 AM on the 16th and saying we would probably be one of the first in the world.”

Scotland's two largest churches, the Catholic Church and the Church of Scotland, have criticized the law, saying they would not wed gay couples. However, other religious groups, including Quakers, Buddhists and the Pagan Federation, support marriage equality.

Scotland introduced civil partnerships for gay couples in 2005.