Dispute between landlord an tenant , how much to pay in rent ?

This is why you have a contract!

Informal arrangements like this are a recipe for disaster. If the tenant fails to pay the rent, you've got no legal recourse. If you want to evict the tenant further down the line, it'll be very difficult. If you take a deposit without placing it in a proper deposit protection scheme, the tenant can sue you for 3x the amount of the deposit.

You shouldn't be a landlord if you don't know what you're doing.

Don't understand.. tenant moving in May so contract starts then...why backdate rent, surely that illegal..tenancy starts when landlord and tenant agreed they move in...start of tenancy. Landlord sounds clueless op so check they done all the checks and put your deposit in a scheme.

Tenancy starts from the day tenant moves in. The issue is lack of contract (you) and lack of communication (both sides).

Lesson learned for next time, always have a contract/tenancy agreement regardless of the relationship.

I'd suggest that the landlord now needs to messgae back and acknowledge receipt of the first months rent, confirm that this now starts the rental agreement from 1st May 2024, state that the next months rent is due 1st June and every 1st going forward for the duration of the agreement, and state that keys are available for collection at the lodgers convenience.

Then put it into writing properly with a lodging agreement signed by both parties when the keys are picked up.

Landlord here - they pay from date of moving in

If you are holding the room you give them a deadline if you want them in by a certain time

The landlord here sounds a bit clueless tbh

There's no contract and this all seems very informal so lodger doesn't pay until they moved it.
If the landlord chose to keep the room open and not specify the date the arrangement started then that's on them.

Not a great way to start living together is it?!

Landlord needs to draw up a contract and do things properly. That's their responsibility.

Has the landlord (you?) Replied yet??
They asked to pay on 1st no response.
Sent message to saybtheyd paid, then no response.
Although I guess now they've paid it doesn't matter that they haven't moved in yet.
If you are landlord I'd send message now confirming paying from May is fine and ask them to confirm when they'd be moving.
Presumably there has been more contact than what you've noted though as at dome point a discussion has taken place about when the rent should be due from.

The landlord didn't send correct bank details until 19 April.
Tenant asked if they could pay on 1 May.
It doesn't appear that the landlord responded either way.
I'd read that as the rent being due from 1 May. Rent day is first of every month going forward.

given that the Landlord is being so unprofessional about the whole affair - no contact available before the lodging arrangement, nothing in place yet, because knows the lodgers mother, I'm guessing the room wasn't rented out before, wasn't about to be rented out on the open market, and from the context is a favour to a family friend.

Get a contract in place ASAP, written house rules that landlord and the lodger are both clear on, and try and keep it on a more professional basis - otherwise LL risks giant row over something tine, and potential blow up with friend.
And only charge rent from when tenant/lodger moved in. If LL feels aggrieved by this, it's their fault for not being more organised and professional from the outset.

Since there is no contract and lodger did not move in rent is due from date they moved in.
The fact the landlord could have rented to someone else is by the by. You chose not to and also chose not to get a contract drawn up.

If that is the only communication between the two then they look to have been as lax as each other surely.

If they only move in in September is a moot point really. I would say that the onus is on the potential landlord to pin down moving in dates, key handover etc.

They are the one with the 'professional' position in this transaction. They are the one losing out on income. It's in their best interest to get the details confirmed.

Sounds like the potential lodger is young and easy come easy go about the whole thing.

The rent has been paid on the first of May, it's now the 5th and your OP implies the person has still not moved in?

Tenant says £400 on May first will cover May, doesn't want to pay for March or April. Wants to move in asap.

Meant to add that at least now the lodger looks to be committed.

Landlord can either accept or say sling your hook, I'm keeping the cash for messing around, and lose out on a lodger and a friend (lodger's Mum).

If landlord was that bothered they should have chased up, got commitment and dates in writing, or readvertised the room.

A contract can be verbal and to be effective does not have to be written. The contract is whatever you have both agreed.

19th April isn't early April.

Well I would imagine a landlord wouldn't have kept the room until September. I think though it needed to be more concrete. Landlord should have been clear that payment was due on the 10th of March and have provide bank details. Landlord should have contacted tenant on 10th or 11th asking why they hadn't moved in and for payment.
Obviously likewise tenant should have communicated better too.
Understandable if you as landlord want to cancel arrangement now due to being let down on moving in date although to me there really should have been more formal communication and expectations. ²

You'd be an absolute mug to keep a room that length of time with no payment.

I take it you're the landlord.
Seems without a contact in place you should accept the money from may. Unfortunately with informal arrangements this kind of thing happens. I also think landlord probably should have contacted sooner to chase up and confirm payment would be due.
If landlord had said OK you are moving in on 10th, key is ready whenever you are, here are my bank details please pay by this date then it would be clear they needed to pay from March but as its been done so casually I don't think landlord can insist on payment here.

Rent should be paid from the day the tenant had access I.e whenever they picked up the keys

No it doesn't. The contract commences on that day, but the tenancy does not start until the tenant moves in. And as the person will be an excluded occupier, it isn't a tenancy it's a lodger agreement.

It all sounds confused and lacks clarity. I wouldn't want to do business with either of you.

So as there was no contract - payment is still only due from when lodger moved in.