Ebay have asked for my NI for reporting to HMRC. I have a business and complete a self-assessment. My eBay sales are nothing to do with this. I'm a private seller. Mostly selling, from my loft, issues of Radio Times from the past 50 years. So I exceed the 30 items per year threshold for eBay to report to HMRC. Sometimes my sales probably exceed the £1740 per year threshold. Ebay say they will deduct postage costs bought via eBay before reporting. But what about my postage costs? I prefer to support my local self-employed postmaster (as postmasters are self-employed), and buy my postage there. My expenses, mainly postage, are typically 40% of the sale price for each issue. Will I be able to account for this to HMRC, and have them deducted? From every £1000 my profit is about £600. I do not get £1000.