Yes - assuming the primary purpose of your visit to London is to attend the conference. The allowable costs would include, travel, hotel, subsistence (but not alcohol - sorry!) seminar costs etc. However, if you were to take your spouse/partner then any costs relating to their stay would not be regarded as a business expense.
I am afraid that if you were to extend your trip to include a few days sight seeing then HMRC might want to argue that the trip was not 'wholly and exclusively' relating to your business and want to omit some or all of the expenses.
How do I work out the amount I can claim for using my car for work using the "pence per mile" method?
The use of the 'pence per mile' method for the selfemployed is only allowed as an Inland Revenue concession (not in the legislation but for simplicity the Inland Revenue will allow such a claim). To qualify your business turnover must be below the VAT threshold, currently £67,000, and you must be either starting in business or changing your vehicle. You can only change from the traditional method of claiming car-running costs to the 'pence per mile' basis when you change your car. If you do not change your car you cannot change your method of claiming.
The first thing that you must do is keep a detailed mileage log.
This should record ALL business and ALL private miles on a daily basis. You must also still retain you receipts for things like petrol, insurance car tax etc.This is your 'evidence. Once your have passed your accounting year-end then you apply the simple formula to your business mileage. That is the first 10,000 miles attract a rate of 40pence per mile with the excess mileage attracting a rate of 25pence per mile.
For example a photographer who completes 16,000 business miles would claim:
10,000 miles at 40p = £4,000
6,000 miles at 25p = £1,500
TOTAL CLAIM = £5,500
The Societies of Photographers Convention and Trade Show at The Hilton London Metropole Hotel ...
You have 224 days until The Societies of Photographers Convention starting on Wednesday 10th January 2018