STS vs Non-STS: When Securitisation Plays by the Rules (and When It Doesn’t)

Some financial products arrive wearing a neat suit and carrying all the right paperwork. Others turn up late, slightly rumpled, and insist they’re more fun anyway. The securitisation market has both, and the velvet rope dividing them is the STS label.

STS – short for “simple, transparent and standardised” – was born from Regulation (EU) 2017/2402, otherwise known as the grand clean-up act after the 2008 crisis. The UK kept it post-Brexit, in slightly altered form, and the idea was straightforward: restore trust in securitisation by rewarding deals that are clear, well-structured, and sufficiently dull to make regulators sleep better at night. Deals that pass muster get to strut around as STS. Those that don’t remain entirely legal, sometimes more lucrative, but a touch less respectable.

What Makes a Securitisation STS?

The Regulation sets out a checklist under three headings: simplicity, transparency and standardisation. Tick all three, and you’re in.

• Simplicity means the deal is built on one clear type of loan, all made in a sensible way. Think of a pool that’s all mortgages, or all car loans, or all credit card balances. What you don’t get is a jumble of unrelated assets thrown together just because someone fancied it. Regulators also banned the Russian-doll trick: you can’t make a securitisation that’s backed by slices of another securitisation. And the assets themselves must be genuinely transferred into the issuing vehicle – what lawyers call a “true sale.” That way, investors really do have a claim on the loans in the pool, rather than being fobbed off with a clever bit of financial smoke and mirrors.
• Transparency means investors can actually see what they’re buying. Issuers must hand over detailed information on the loans, the borrowers, and how the pool is performing. The documents explaining the structure must also be published. And it’s not a one-time filing – the information must be kept up to date, using official templates filed with regulators. The aim is to stop securitisations turning into black boxes where nobody knows what’s lurking inside.
• Standardisation is all about keeping the machine well-oiled. Everyone’s role in the structure must be clearly defined, and loan servicing must follow proper standards, so payments are collected and passed on smoothly. Interest-rate and currency risks must be managed rather than ignored, and cash flows are generally expected to pay down in order, unless there’s a good reason to do otherwise. And then there’s the five per cent rule: the bank or lender must keep a slice of the deal, so they care about performance just as much as investors do.

The Three Official Categories

The STS framework doesn’t paint every deal with the same brush. It sets out three categories that can qualify if they meet all the rules.

• Term securitisations – These are securitisation’s meat-and-two-veg. Imagine a box filled with one type of loan – mortgages, car loans or credit cards. That box (the special purpose vehicle or SPV) then issues bonds to investors, who are repaid as the borrowers pay back their loans. Because the contents of the box don’t change, everyone can see exactly what’s in it from day one.
• ABCP programmes – Asset-backed commercial paper is the short-term version. Here the vehicle issues very short-dated IOUs (often less than a year) and continually replaces them. Instead of one box, there can be several smaller boxes being financed at once, which makes it busier and more complex. To keep things safe, the rules apply twice: each little box must qualify, and the whole set-up must meet extra standards on cash back-up and risk controls.
• Synthetic securitisations – The cautious cousin. In this case, the bank keeps the loans but passes the risk of them going bad to investors using contracts or guarantees. The point is to reduce the capital the bank must set aside. Regulators only allow a very narrow, tightly policed version to count as STS, because in the run-up to 2008 the more exotic versions caused serious damage.

Non-STS Securitisations

Not every deal makes the STS grade. Those that don’t are still perfectly legal and often make up some of the liveliest corners of the market. Even so, they must still follow the Securitisation Regulation’s general rules – things like the five per cent retention, proper disclosure and investor due diligence. What they miss out on are the added perks that come with STS status, and we’ll come to those in a moment.

Non-STS tends to crop up where the pool is more varied or the structure more bespoke. CLOs, with their shifting bundles of leveraged loans, fall outside the “similar loans” test. CMBS, built on chunky commercial property loans, are too diverse to qualify. Re-securitisations and complex synthetic trades are kept firmly out as well.

Yet far from playing second fiddle, these markets are thriving. The attraction is obvious: higher yields, customised structures and access to assets that don’t fit neatly into the STS template.

Legal and Regulatory Consequences

For issuers and originators, the STS label isn’t something you can just slap on and hope no one notices. To claim it, the originator and sponsor must jointly notify the regulator – the FCA in the UK or ESMA in the EU – and publish a formal statement confirming that every box has been ticked. Getting this wrong isn’t just embarrassing; it can mean regulatory sanctions and liability for misrepresentation. Deals that don’t qualify can still go ahead perfectly lawfully, but they must not be described or marketed as STS.

For investors, the perks of STS are clear. Under the Capital Requirements Regulation, banks and insurers holding STS paper enjoy lower capital charges, making these investments more efficient to keep on their balance sheets. The label also brings a degree of regulatory comfort, otherwise known as reassurance, that the deal has passed a recognised set of safeguards. That doesn’t mean investors can put their feet up – the due diligence duties remain, and they still need to do their sums.

Non-STS transactions, by contrast, attract heavier capital charges and lack the shortcut reassurance of the STS label. Yet for many investors, that’s a price worth paying in return for higher yields and more flexible structures.

The Last Word

STS was created as securitisation’s good-behaviour badge – proof that the market could be tidy, transparent and safe enough to stop giving regulators nightmares. It gives issuers a lower cost of funding, investors a lighter capital load, and the whole market a stamp of respectability.

But that hasn’t killed off the non-STS world. Far from it. The more complex, tailor-made deals continue to thrive, appealing to investors who prefer higher yields and bespoke structures over regulatory comfort.

What we are left with is a market with two distinct personalities. One wears the sensible suit and plays strictly by the handbook. The other is more complicated, a bit flashier, and often more rewarding. Both have their audience – and securitisation would feel incomplete without them.