Thanks for your question - I am Sam and I am one of the UK tax experts here on Just Answer.
Is this a limited company - in which country is this company registered, where do you under take the work (here or in the UK)
Are you a UK resident or citizen?
Wy have you not yet registered the business with any tax regime?
Do you draw a salary or dividends
Please advsie further
Thanks for your response
Have HMRC agreed that this is an hobby? As if they have not then you have to declare this income. And it would seem this is NOT a company its just income from running this game ? Can you clarify as it would appear you should have been declaring this income to HMR from its start position - so when did you begin this ?
Then you must inform HMRC that you started earning from this 5 months ago as I am afraid ALL income is liable to tax consideration and only HMRC can determine whether they feel this would be a hobby and there not be a need to declare.
You should have registered for self employment within 3 months of this starting so you will incur a late charge for registration. and even if you earn less that £10,600 for 2015/2016 and less than 311,000 for this tax year - you still have to make a full declaration of income.
Then whether you stay as a sole trader business - or choose to go down the route of setting up a limited company you then declare the total income earned, and offset this with the expenses you have incurred - and then are only considered for tax and National Insurance on the net amount - which is then added to any other income you have to full consideration.
This is done as HMRC will send you a self assessment tax return to fill in after you have registered. Initially they will ask for one for the period 06/04/3015 to 05/04/2016 - and again after each 5th April
Let me know if I can assist further