If you really don't expect to make a profit then I wouldn't do anything about a tax return. But make sure you keep good records of sales and costs so that if you do make a profit you'll be able to declare it accurately. If you make a very small profit - say �100 or so - you would probably be able to declare it as "miscellaneous income" but if it gets much larger you'll have to register your self-employment, after which you'd get a tax return with both emplyment and self-employment pages. If you do register your self-employment, ask HMRC about "low earnings exemption" from Class 2 NIC. Don't forget that if you make a loss you should declare that, too.