My other half is now officially running Bleed Ink as well as her new business Gl'mour as a sole trader. We're starting to go through the ball ache of tax etc but are wondering if there's any tax benefit to Gl'mour paying Bleed Ink for print services? For example.. she prints 100 sheets at a cost of £20, invoices that from Bleed Ink to Gl'mour at cost price. It goes down as a Gl'mour business expense so is offset against tax but the original invoice from the printer is also a business expense for Bleed Ink so could in theory be off set again? Is that allowed as a sole trader or would she need to be keeping two sets of books for the two companies?