Renting out a room

If you have the space, renting out a room is by far the biggest structural extra income source on this list: hundreds of euros a month, every month.

What it pays

Room rents in most cities run between €400 and €800 a month. Many countries have a tax-free allowance for renting out a room in your own home (rent-a-room schemes) — check the threshold where you live, because below it the income is often untaxed.

Check first

• Renting yourself? You almost always need your landlord's permission to sublet.
• Own with a mortgage? Some mortgage terms require the bank's consent.
• Benefits: a lodger can count as a co-resident and affect housing support — run the numbers first.
• Local rules: check your municipality's requirements for live-in landlords.

A lodger is a relationship

You're bringing someone into your home, not installing a cash machine. Take time choosing, agree house rules up front, and put everything in a simple contract with a trial period. A good match makes this the calmest €500 a month there is; a bad one makes your house stop feeling like home.