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By Priya Nandra, Credit & Risk Editor. Published 7 July 2026. Last updated 13 July 2026.
"Thin file" is underwriting shorthand for a company whose credit record barely says anything: no previous borrowing, minimal filed accounts, a short trading history. Directors tend to hear it as a verdict. It is not — it is a description of missing evidence, and the practical question for any lender is what evidence to read instead. This article sets out what a thin file actually is, what gets read in its place, and — the part directors can act on — which of those substitute signals you can improve within months rather than years.
What a thin file is, precisely
A company's credit file is held by business credit reference agencies and built from public data — Companies House filings, county court judgments, in some cases payment-performance data shared by suppliers and lenders. A new or small company generates very little of it. A one-year-old limited company with no borrowing, micro-entity accounts and no trade-credit reporting has a file that is thin in the literal sense: there is almost nothing on the page. That is different from a bad file — a CCJ, a default, a history of missed payments — which is thick with the wrong content. Thin means unknown; bad means known and adverse. Underwriters treat the two completely differently, and directors should too. We cover the agencies themselves in the directors' guide to business credit reference agencies.
What gets read instead: the bank account
When the credit file is silent, the single richest substitute is the company's bank transaction history — which is why read-only Open Banking connections have changed underwriting for young companies more than anything else this decade. Six months of real transactions shows what no credit score can: whether revenue is regular or lumpy, whether the balance trends up or down, whether there are gambling transactions or bounced payments, how close to zero the account runs, and whether existing obligations are met on the dates they fall due. A thin-file company with a clean, steadily trading account is a fundamentally different proposition from a thin-file company whose account bounces along its floor — and the credit file cannot tell them apart. The bank data can. We set out our own reading of it in smarter statement analysis for fairer decisions.
What gets read instead: the public record
The Companies House record is the company's public face, and underwriters read more from it than most directors expect. Confirmation statements and accounts filed on time signal an administered, attended-to company; late filings signal the opposite, fairly or not. The incorporation date frames trading history. The officers' record shows whether directors have a trail of dissolved companies behind them. A registered office that matches reality, a sensible SIC code, share capital that is not theatrical — none of these is decisive alone, but together they form a picture of whether someone is minding the shop. Every item on that list is free to get right.
What gets read instead: the absence of bad news
For a thin file, the checks that matter most are often negative ones: no CCJs against the company, no CCJs or bankruptcy against the directors personally, no disqualification history. A thin file that is also clean passes the most important test available to it. Where there is adverse history, the honest position is that it weighs heavily precisely because there is so little else on the file to outweigh it — a director in that position should read CCJs explained for company directors before applying anywhere.
What thin-file lending honestly costs
Less evidence means more uncertainty, and lenders price and size for it. In practice that means smaller opening amounts, shorter terms, and in much of the market a demand for a personal guarantee from the director — importing personal risk to compensate for corporate opacity. Our own approach is different in one structural respect: we lend to the company without personal guarantees, and we manage thin-file uncertainty by keeping amounts small — £50 to £500 — and terms short, rather than by reaching into the director's personal assets. Which approach suits a given company depends on the sum needed; the trade-offs are set out in no personal guarantee: what it means.
What a director can actually do
The useful part. Most substitute signals are improvable on a timescale of months, not the years a credit history takes to grow.
- Run the business through a business account, exclusively. Six months of clean, separated transaction history is the strongest thin-file evidence there is. Mixing personal spending into the company account muddies the one document that speaks for you.
- File everything on time. Accounts and confirmation statements, even micro-entity ones. It is free and it is read.
- Meet every existing obligation on its date. Rent, VAT, the card bill. Payment behaviour in the bank data is the closest thing a thin file has to a track record.
- Consider a small facility used lightly and repaid on time — borrowing history has to start somewhere, and a modest, well-handled first facility is how files thicken. The worked pattern is in looking beyond your credit history.
A thin file is a company the data has not caught up with yet. The good news buried in that sentence: unlike a damaged file, which takes years to repair, a thin one fills in fast — and mostly with evidence the director controls.