Alternatives to Treasury Bills: Why the invoice market offers better terms and similar yields

In recent years, Treasury Bills have become one of the most popular products among Spanish savers. After more than a decade of near-zero interest rates, the rise in interest rates brought this traditional public investment instrument back into focus.

However, those returns that reached 4% in 2023 are no longer as attractive. This has led many investors in 2026 to ask an increasingly logical question: are there alternatives that offer similar returns but with greater flexibility?

In this context, the short-term business financing market, especially through commercial invoices, is emerging as an increasingly attractive alternative for those seeking returns, short timeframes and diversification.

Treasury Bills: what they are and why they became so popular

Treasury Bills are short-term public debt instruments issued by the State, typically with maturities of 3, 6, 9 or 12 months.

During the 2023–2024 period, they experienced a real boom among Spanish savers for several reasons:

• Rapid rise in interest rates


• Perception of high security as they are public debt


• Returns clearly above bank accounts

For many conservative investors, they became the simplest way to obtain some return without taking on significant risks.

However, as the interest rate cycle stabilises, important limitations begin to emerge, prompting many investors to look for alternatives.

Limitations of Treasury Bills that many investors discover later

Although Treasury Bills are considered a safe product, they also have some drawbacks that should be taken into account.

Relatively long terms for those seeking liquidity

Although they are considered short-term investments, in reality capital is usually tied up for between 3 and 12 months.

This means that investors cannot easily access their money before maturity without going to the secondary market, where prices may vary.

For those seeking frequent capital rotation, these timeframes may be too inflexible.

Limited returns after taxes and inflation

Another important aspect is that returns from Treasury Bills are subject to taxation as income from movable capital.

After taxes, real returns can be significantly reduced, especially when compared with other moderate-risk investment alternatives.

Moreover, when inflation remains close to or above these returns, real gains may be very limited.

Limited diversification capacity

When investing in Treasury Bills, the investor concentrates their capital in a single issuer: the State.

Although Spanish public debt carries low risk, from a financial perspective it is always advisable to diversify across different asset types and sources of return.

The invoice market: an alternative gaining momentum

Faced with these limitations, an alternative is gaining increasing attention among retail investors: financing commercial invoices of companies.

This model allows investors to finance the early collection of invoices issued by solvent companies, receiving a return in exchange for advancing that capital.

In other words, the investor participates in real business operations, with very short timeframes and predefined returns.

Why the invoice market offers more attractive timeframes

One of the main advantages of this type of investment is its much shorter duration compared to many traditional products.

While Treasury Bills usually have maturities of several months, invoice financing operations typically range between:

• 30 days


• 60 days


• 90 days


• 120 days

These timeframes allow investors to rotate capital more frequently, reinvesting in new opportunities or recovering liquidity when needed.

Similar returns with less dependence on the market

Another relevant aspect is that returns in the invoice market are often comparable to or higher than many conservative alternatives, with one key difference: they do not depend directly on financial markets.

Returns come from the discount applied to financed invoices, meaning they are linked to a specific commercial transaction rather than to interest rate movements or stock markets.

This makes business financing a form of investment more closely tied to the real economy.

Inversa: access to the invoice market for retail investors

In this context, specialised platforms such as Inversa allow investors to easily access the business invoice financing market.

Through this model, investors can participate in previously analysed operations with characteristics such as:

• Short terms, generally between 30 and 180 days


• Returns known from the outset


• Ability to diversify across different operations


• Direct participation in financing Spanish SMEs

This makes it possible to build what many investors call an invoice portfolio — a strategy based on investing in multiple short-term operations to generate recurring returns.

Treasury Bills vs invoice market: key differences

Treasury Bills

• Public debt


• Terms of 3 to 12 months


• Moderate returns


• Low diversification

Invoice financing

• Real business economy


• Terms starting from 30 days


• Competitive returns


• Diversification operation by operation

This does not mean one should completely replace the other. In fact, many investors combine both options within a diversified strategy.

Diversification: the key to smart investing

Rather than looking for a single perfect investment, the key to protecting and growing wealth lies in combining different assets and time horizons.

In this context, many investors use Treasury Bills as a conservative component of their portfolio, while the invoice market provides additional returns and greater flexibility.

A new way of investing in the real economy

In an environment where investors increasingly seek predictability, liquidity and diversification, the invoice market is emerging as an attractive alternative to traditional savings products.

Through platforms such as Inversa, it is possible to participate in real business financing operations, with short terms and competitive returns, while also contributing to the growth of Spanish SMEs.

If you are looking for alternatives to Treasury Bills that allow you to maintain liquidity and diversify your portfolio, exploring the invoice market may be a valuable step within your investment strategy.