Single room for two in hotels and B&B's

I'm not quite sure I understand your dilemma. just because you are booking online doesn't mean you can't contact the hotel directly with questions before you book.

Most online booking agencies such as booking.com or hotels.com, etc (or the hotel's own booking site) will state the maximum number of persons allowed for a particular room, sometimes it's an icon showing number of little people. I will say that most single rooms in European hotels are truly for singles and the bed is most likely a twin-sized bed, not a double bed. That's not always the case but usually. If they sell it as a single room only one person is allowed. The reason doubles are more expensive is that they sell hotel rooms per/person, not per/room like here in the US.

I have always understood it that a "Single" is for one person - one bed - frequently a twin, a "Double" is for two people 1 bed a full or queen sometimes (rarely in a B&B) a king , a "Triple" is for three people - 3 beds - frequently 3 twins, etc...

The higher charge for a double room is also to cover the additional utilities (water/electric) used by 2 people over 1, the additional laundry for two people (towels ect) and generally breakfast for two vs one.

Even if you find the hotel on one of the major booking sites - Booking.com, Hotel.com, etc visit the hotels website and book direct with the hotel - this saves the hotel the % they would pay to the booking company and some will pass that on to the customer either directly in the room rate or with some other means - a free drink upon arrival or transportation tickets. If the hotel does not have online booking on their website send an e-mail with your dates & needs - they will reply with a rate and answers.

Listing rooms on the major booking engines is the best way for smaller properties to get exposure but they pay a big percentage for that. Many appreciate your booking direct - this way you do have communication with the property directly via email or phone if desired.

A single room in Europe has a twin size bed only if you're lucky. It often has a cot-sized bed. (I almost always travel solo, and I consider myself lucky if my room has anything larger). Furthermore, single rooms are usually smaller (particularly narrower) than doubles; there often isn't room for a larger bed. So, not only will a hotel not let two people stay in a single room, but it's usually not even possible or desirable.

You need to rent a room for two people, whether you want to share a bed or have separate beds. I don't find that these are "much" more expensive than singles, but they do indeed usually cost more; it's not as common for the rate to be "$xxx, single or double occupancy" as it is in the US. As I said, that's partly because double rooms are larger. A "double for single use" costs more than a single for this exact reason (it's usually less than a double for two people, but only a bit).

And yes, for any hotel you're interested in, contact them directly by e-mail. For my upcoming trip to Switzerland, I was able to get rooms that were not showing on the hotels' own booking sites, or on third party sites such as Hotels.com. I also got better prices (several offered Rick Steves discounts).

In France you must book by number of people in room. Two people in a room is a double/twin room period.
A couple complained as they had booked a suoble room in Paris, and arrived with their 18 month old child.

They were turned away, hotel had no triple rooms available so they were booted out. They have strict occupancy limits and fire codes.

Do not book a single for two people.

Two people can't book a single room, only a double. Thank goodness single travelers have some ways to save money; the cost of a single room is usually more than half of a double room.

My wife and I have found that European beds are frequently smaller and we are better off to request twin beds because a worn out mattress on a double bed rolls both of us to the middle like a folded taco. Further, a lot of place that say they have big beds actually have only two twins pushed together.....

Single rooms and double rooms as sold on many booking websites are frequently the exact same room. Don't believe me? Look at the pictures of the rooms online. It is just that hotels in Europe charge per person, so, thus, the difference in cost. If you booked a single room and showed up as two people, you would no doubt be charged extra at a rate that would be higher than had you just went ahead with a double booking in the first place.