First of all you cannot round off the figures, the taxman won't like it, if you get a simple tax inspection and the taxman notices that the figure are not correct he will then do a complete tax investigation, which is very costly
Claiming for an office in the home, what the tax office allow is if you work from home and you don't use a separate room for it, then you can only claim £2.00 per week. ( this figure can change from office to office, this figure is what Birmingham taxman allows, so they said anyway)
If you use a spare bedroom them firstly there must be no bedroom furniture in it, this also applies to storing your clothes and bedding.
You cannot claim any mortgage or rent allowance unless you have purchased this property for the business.
You can only claim a percentage of the Council Tax - Electric and Gas you use, if you are on a water meter then you have to take off you personal use and work out your business use, if you are trad then this won't apply.
The percentage you can claim is worked out by you counting how many rooms there are in you home ( you cannot count the kitchen bathroom or hall/corridor - cloakroom or garage) you then divide this room or rooms that you are using for your business only to work out the percentage.
For example you live in a 3 bedroom home with 1 living-room and 1 dining room, you use one of the bedrooms as an office, you have 5 room in your home you use 1 for the business, so the percentage you can claim is 1/5 or 20%.
Telephones, if you use the telephone for personal and business use then you have to work out what the percentage of use for both is.
If you only use the phone for business use then you can claim all 100%.
You have claimed for a computer, you need to show that this is only used for the business, so if you have a office and the computer is in the living room then the taxman will assume that it is used both for business and pleasure.
Vehicle's
If you have a van then you don't normally have to declare a personal usage, unless its excessive.
There are 2 different way to claim for vehicles, one is actual vechicle running costs or mileage.
Mileage is worked out on 40p for every mile that you use up to 4000 miles then it drops down to 25p.
Vehicle costs are all the normal running costs, but excluding the vechicle purchase price, which is classed as a "writing down allowance".
Once you go one way or the other then you have you stay on that rate until you replace the vechicle, you cannot change every tax year.
Writing down allowances
If the item costs more than £200 then you can claim 50% in the first year the 25% per year until you recover the total cost, if you sell the item later then this money must be declared as a capital allowance.
If you buy a pole that costs £1000 and it breaks- get lost or is stolen, then you can claim the total cost in that tax year.
Income
The taxman is going to want to see where you income comes from, kept a list of all your customers that you have cleaned for in that week, including the ones who have not paid yet, if they don't pay for any reason then you can claim this back as a debt that is written off.
Lastly on the figures that you have shown then you won't be liable for any tax to pay unless you have a second income that has pushed you passed your personal allowance.
But for those that have made a profit that they have to pay tax on, then in 6 months time the taxman is going to want you to pay 50% of this tax figure up front as well as the tax due for that year.