The new mum and dad are reported to have applied for a passport for Prince George ahead of their forthcoming tour of Australia and New Zealand.
The nine-week-old's application will have set the Royal couple back £46, and will bear the baby's full title of George Alexander Louis of Cambridge.
Kate and William's trip has echoes of an infant Prince William's visit Down Under 30 years ago, when at just nine months old, he visited Australia with his parents Charles and Diana.
At the time, the Queen had to give permission for William to fly on the same plane as his dad, as Royal protocol dictates the heir to the throne and the next in line should not fly together - this was vehemently overruled by Diana who would not allow her son to travel separately.
The Queen is now expected to allow little George to fly on the same jet as his mum and dad for the trip - just as he joined them both on their plane to Balmoral last week.
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