Interest cover ratio is the rent divided by the mortgage payment, tested at a stressed rate rather than the rate you pay. A company or a basic rate taxpayer is typically tested at around 125%, a higher rate taxpayer at up to 145%. The same property and the same rent therefore support noticeably different loan sizes depending on who is borrowing.
Limited company lending is assessed differently from personal lending. The company is usually a special purpose vehicle with nothing in it but the property, so the lender takes a debenture and personal guarantees from the directors and underwrites the people behind it. The SIC codes on the company have to match what it actually does.
From four mortgaged buy-to-let properties you are a portfolio landlord for lending purposes. The lender then underwrites the whole portfolio: aggregate loan to value, overall rental cover, and usually a business plan and cash flow alongside the application. A schedule that does not reconcile with the mortgage statements is the quickest way to stall a straightforward purchase.