HOW MUCH DO BOOMERANG KIDS COST?

Check which bills will increase with the arrivals of your offspring. If you’re a single parent, you could lose your 25pc council tax discount.

Utility bills will also cost more but the amount will depend on the type and size of your home, what time of year your child moves in and their consumption.

An extra person living in your home adds £90 to £120 a year to your energy bills, according to energyhelpline.com, the switching site. Two boomerang kids would cost between £177 and £236 a year.

Kate Talbot, a chartered financial planner at Shore Financial Planning, said you could take a meter reading when your offspring came home and another one a month later to work out how much to charge.

Water bills will also go up. Southern Water suggested the average two-person household’s water bill is £425 a year, or £545 if there are three of you living in the house.

Expect food costs to rise – probably significantly. Ms Talbot said your grown-up child could easily add another £60 a week to your supermarket shop, costing an extra £240 a month. And if they’re fussy, or help themselves to your secret supply of biscuits or port, you could end up paying even more.

What you pay towards your rent or mortgage won’t change with the arrival of another person, so you need to decide whether it’s fair to ask for a contribution.

Ms Talbot said most parents who ask their adult kids for rent tend to do so to ensure they’re still “paying their way” while helping them get on the ladder.

She said there’s a lot of pressure on millennials to buy their own property, as their parents and grandparents did. Parents who are used to supporting their children can feel guilty if they aren’t able to offer a lump sum to their children to be used as a deposit.

Instead, some prefer to offer them a cheap place to stay to give them the opportunity to save it themselves.