Q My husband and I have flown domestically several times with our baby, now 10 months, and we're thinking of heading to London soon. Will we get the same sweet deal: no charge for her if she sits in my lap?

A Sorry to bear bad news. While parents can carry a lap baby for free on domestic flights, the policy does not apply when you hop the pond. Most airlines charge 10 percent of the adult fare plus fees and taxes to keep a baby under 2 years old on your lap for overseas flights. And stand warned: Last month, Hong Kong-based Cathay Pacific raised the percentage to 25. Depending on the cost, you may want to consider buying your child a seat. I remember fondly those early years of my daughter's fare-free life. But, honestly, after a few flights, I bought her a seat. It was safer on two counts: She was strapped into her car seat in the event of turbulence, and I was less likely to suffer muscle cramps from holding a sleeping 20-pounder.