Can I book London while on the road outside of town?

My word...yes, your budget is low as far as I am concerned. September is very busy so if you want the better lodging for your budget you should book now.

BTW, it's better to think in GBP for London. $100 = about 77GBP?

What kind of dollars ? Canadian, American , Australian etc - better to think in gbp .

We try to keep hotel rooms to 100 GBP a night in London - it’s not always easy .
That’s a tight budget for central london

With a budget that is frankly TINY for central London, you really need to be booking in advance and with a lot of time to search.

Otherwise you’ll end up in a hostel or a really bad hotel.

Actually you probably will, anyway, if you only want to spend $100.

You say “don’t laugh,” which means you’re aware it’s a low budget. Have you looked already? Have you worked out what that budget will get you in London?

Try booking Falcon Hotel, Norfolk Square, it’s a five minute walk from Paddington Station. It’s in your budget, it’s nice and clean and they have breakfast included.

As the others say "$100" is meaningless unless you say which type of $ you mean.
Expect to pay £100-£150 for a basic hotel room if you book in advance. 3 days before will cost you more. Anything cheaper is a hostel without a toilet in the room.

For an idea of prices, see the Premier Inns chain, which is an inexpensive basic chain with many locations in central London (and all over the UK): https://www.premierinn.com/gb/en/home.html

I would not even consider it. The free as a bird days are over, especially with a super tight budget. I honestly wouldn’t even go to London with that tight of a budget unless you’re a student or young at heart and willing to hostel and have a very budgeted trip.

Ok, I get it. Will check in the GBP120 range. Hostels are not for us - couch or floor in the 60s was sufficient.

Thanks for eye-openers everyone,

"Be yourself, everyone else is taken." - Oscar Wilde

Look at the Premier Inn Hotel Chain. Not fancy (I would bring my own toiletries) but clean and good value. You save money by reserving in advance. I stayed at Premier Inn London Waterloo (Westminster Bridge) last month and had a very reasonable rate and a great stay. It was quiet, clean, comfortable and well located to walking places and public transport.

To give you a litle idea of how prices change over time. I booked 6 nights at the non-refundable rate of 480 pounds about 6 months in advance. (average of 80 pounds a night). By the time it was the week before my booking, the 6 night rate non-refundable rate had risen to 730 pounds. Pricing is dynamic. As demand goes up, so do prices.

Also Travelodge, which is similar to Premier Inn. No frills but comfortable. You'll certainly make your budget if you're prepared to stay outside central London and travel in. For example I'm staying at the Travelodge in Teddington this summer for a wedding at Hampton Court. It's very reasonable and it's a half hour train ride into London Waterloo. It's also the right side of town if you're departing out of Heathrow. Obviously it means no opportunity to pop back to the hotel for a quick power nap, but if you're happy spending your day up in central London and then coming back to a desirable neighbourhood in the evening with nice restaurants, the River Thames and lovely parks with roaming deer on your doorstep then give it a go - the prices might just be too good to miss!

There are several small inns/b&bs in Bloomsbury behind The British Museum in the neighborhood of University College London. They are very reasonably priced for London...nothing fancy but clean and well located. They are The Gower House Hotel, the Regency House Hotel, and the Ridgemount Hotel. These are all on Gower Street and there are several others as well, right around the same price range. I have stayed at the Regency House Hotel and it was absolutely fine...teeny tiny rooms but clean and the staff was friendly. If you end up staying in any of these ask for a room at the back as the street does have some traffic. These are probably the best priced little places to stay in London that are somewhat cheap and not flea bag hotels!

In a similar vein, the Arosfa Hotel on Gower Street or any one of a number of small hotels in Cartwright Gardens, also in Bloomsbury.

British university student accommodation could still be available in early Sept.; a step up from hostels and cheaper than a hotel with a choice of accommodation, also often well located for transport and sites.

For some more ideas of inexpensive accommodations, look at the EuroCheapo London page: https://www.eurocheapo.com/london/

I liked the Hub by Premier Inn Goodge Street: https://www.premierinn.com/gb/en/hotels/england/greater-london/london/hub-london-goodge-street.html. Note that for two people, you'll want a "Bigger" room, which is still small but workable for two. The regular room was comically small (though well laid out) even for one, and will not work well for two (although it is sold as a "double").

There are websites selling off surplus hotel rooms for the night of query - Hotel Tonight is one. You can check out what you might be able to get at your price point on dummy bookings.
I also like the Premier Inns for value. Best is pre-booked pre-paid no cancellation rates.

Try the Cherry Court Hotel- Not sure if this is still in Rick’s most current book, but I found it a few years ago. A great central location in Victoria, near the bus station and underground- about 70 pounds a night- no-frills, but clean, safe and run by a lovely family. It’s my go-to hotel in London, but I would definitely make a reservation.