Understanding internal and external sources of finance

Growing a business often takes more than hard work – it takes investment. And for SMEs, that investment can come from two broad sources: internal or external. Each has its own strengths, and the right choice will depend on your goals, your risk appetite, and how quickly you want to scale.

Even with the benefits of internal finance (explained below), external funding remains a popular choice. In 2025, around 50% of smaller businesses used external finance, with credit cards (19%), overdrafts (16%), and leasing and hire purchase (13%) being the most common choices.

In this article, we’ll explain what internal and external sources of finance are, the advantages and disadvantages of each, and how to decide which is right for your business.

What are internal sources of finance?

Internal sources of finance come from within your business. You’re using the resources you’ve already built up – like profits, assets, or cash flow – to fund growth or cover costs. And because the money’s already yours, you don’t have to take on debt or give up equity in your business.

This approach can be suitable if you value control and want to avoid paying interest or dealing with external stakeholders. Many entrepreneurs start this way, reinvesting what they earn to scale at their own pace.

Internal sources of finance examples

• Retained profits: This is the money left over after you’ve paid taxes, expenses, and any dividends. Instead of taking it out of the business, you reinvest it (eg upgrading equipment, hiring staff, or launching a new product).

• Sale of assets: If you’ve got unused machinery or surplus stock, you can sell it off to free up cash and turn unused resources into working capital.

• Working capital management: Make your existing cash work harder by speeding up invoice payments, reducing excess inventory, or negotiating longer payment terms with suppliers.

• Owner’s capital: If you’re just starting out or want to increase your share of a jointly-owned business, you could invest your own money.

What are the advantages of internal sources of finance?

• You stay in control: With no lenders or investors to answer to, you make all the decisions and keep all the rewards.

• It’s cost-effective: There’s no interest to pay or equity to give up, so you avoid the extra costs that come with external finance.

• Flexibility and speed: Using your own money lets you move quickly without filling out application forms or waiting for approvals. And since you won’t be tied to repayments, you can redirect cash as your priorities change.

• Builds financial resilience: Reinvesting profits or optimising cash flow can strengthen your balance sheet, making your business more attractive if you do decide to raise external finance later.

What are the disadvantages of internal sources of finance?

• Growth can be slower: Internal finance is limited by what you and your business have already earned or own, so being completely self-sufficient might not support the scale or speed you need to grow

• Opportunity cost: Money you reinvest is money you’re not using elsewhere, so it’s worth considering whether that money could earn a higher return if it were invested differently

• Shareholder expectations: If your business has shareholders, they might prefer dividends over reinvested profits

• Missed leverage in a low-rate environment: External debt is cheaper now than it has been the last few years (the Bank of England base rate was just 3.75% in May 2026), so using your own money might mean missing out on affordable borrowing that could accelerate your growth

What are external sources of finance?

External sources of finance come from outside your business, such as from lenders, investors, or even the public. They provide a way to get funding when you need more capital than your business can generate on its own, or when you want to grow faster than internal finance allows.

Because the money comes from external backers, you can often secure larger amounts relatively quickly. And in return, you’ll typically agree to terms like interest, fees, or equity, depending on the type of finance you choose.

External sources of finance examples

• Business loans: Borrow a fixed amount and repay it over time with interest

• Asset finance: Spread the cost of equipment, vehicles, or machinery over time, with the asset often serving as security

• Angel investors: Raise finance (and gain mentors) from high-net-worth individuals who invest in early-stage businesses, usually in exchange for equity or a share of future returns

• Crowdfunding: Raise smaller amounts from a large number of people, typically online, in return for rewards, equity, or simply your appreciation

• Overdrafts: A flexible form of short-term borrowing to cover gaps in cash flow, charging interest only on the amount you use

• Trade credit: Suppliers may let you pay for goods or services at a later date, giving you a bit of breathing room with your cash flow

• Venture capital: Professional investors provide funding to fast-growing businesses, usually in exchange for equity

What are the advantages of external sources of finance?

• Access to larger sums: External finance lets you raise more capital than you could internally, helping you fund bigger projects

• Speed and opportunity: When a growth opportunity arises, external finance lets you act quickly if you don’t have the cash on hand

• Flexibility to match your needs: Different types of external finance suit different needs – eg asset finance for machinery or secured/unsecured loans for growth

• Spread the risk: With equity finance, investors share in both the upside and the downside, which can take some of the pressure off you

• Leverage in a stable rate environment: With interest rates being relatively low currently, borrowing costs are more manageable than they’ve been in recent years

What are the disadvantages of external sources of finance?

• Costs add up: When you take on debt, you’ll usually pay interest, fees, or provide returns to investors. Use the cost of debt formula to work out if you can afford the repayments, including taxes and fees. And make sure you’re only borrowing what you need and can repay comfortably.

• Cash flow pressure: With debt, you’ll need to make fixed repayments, even if your income takes a dip. To ease the pressure, look for flexible options where repayments can adapt to your cash flow.

• Less control: If you raise equity finance, you’ll need to give up a share of your business, which could mean sharing some decision-making. To keep as much control as possible, think carefully about how much equity you’re willing to part with and who you bring on board.

• Security risks: Some loans require collateral, like property or equipment. And if you’re unable to repay, you could lose those assets. To minimise that risk, only secure loans against assets you can afford to lose.

• More scrutiny and admin: Lenders and investors will usually want to see business plans, forecasts, and regular updates. While this can mean more paperwork, it also helps you stay on top of your finances and plan for the future. Lenders and investors usually want to see business plans, forecasts, and regular updates, which can result in more paperwork and less flexibility than using your own money.

What's the difference between internal and external sources of finance?

Internal and external finance each have their place in your business.

Here’s a summary of the two to help you compare:

How to decide which type of finance to use

Deciding whether to use your own money or look externally can be overwhelming. And with so many external financing options to choose from, it can be tricky to know where to start.

To make the decision easier on yourself, ask yourself these questions:

• What do I need the money for? If it’s a smaller, short-term need, internal finance is often the simplest and cheapest option. For day-to-day flexibility or covering gaps in cash flow, revolving credit facilities, business credit cards, or short-term loans can help. But for bigger projects, like expansion or major investments, structured external finance like term loans or equity are often more suitable.

• How fast do I need to grow? If you’re looking to scale quickly, external finance is likely the better fit. Slower, more sustainable growth could suit internal finance well. 

• How much risk am I comfortable with? Internal finance keeps risk low, but external finance can spread it out – whether through shared responsibility with investors or structured repayments that align with your cash flow.

• If considering external finance, how much control am I willing to give up? Equity finance means you’ll need to share ownership, while debt lets you keep it – compare equity vs debt in more detail.

External finance sources available through Tide

If you’re considering external sources of finance, Tide could help. We’ve worked with thousands of businesses like yours to help them access a wide range of financing products. Explore the options below to see which works for you.

Debt and loan finance

• Business loans: A lump sum borrowed and repaid over time with interest

• Working capital loans: Borrowing to cover day-to-day expenses and gaps in cash flow

• Short-term business loans: Borrowing designed to be repaid over a shorter period, often for urgent needs

• Start Up Loans: Government-backed loans for new businesses and early-stage founders

Asset-backed finance

• Asset finance: Funding used to buy business assets while spreading the cost over time

• Asset refinance: Releasing cash from assets your business already owns

• Commercial mortgages: A loan used to buy commercial property

• Property finance: Funding to buy, develop, or refinance commercial premises

Cash flow finance

• Invoice finance: Unlocking cash tied up in unpaid invoices

• Revolving credit facilities: Flexible borrowing you can draw down, repay, and use again

• Business credit cards: Short-term credit for everyday business costs

• Merchant cash advance: An upfront cash advance repaid through a share of future card sales

Wrapping up

Choosing between internal and external sources of finance is about balancing control with ambition. Do you want to stay in full control and grow at your own pace? Or are you ready to scale quickly and embrace external support?

It can be a difficult balance to get right, but by carefully considering your options and being clear about your goals, choosing between the two becomes much simpler.

Here’s a reminder of the key points:

• Internal finance comes from your own resources, like retained profits or asset sales, and keeps you in full control

• External finance brings in money from lenders, investors, or the public, letting you grow faster but often with strings attached

• Internal finance is cost-effective and flexible, but it can slow your growth if you rely on it alone

• External finance gives you access to larger amounts and spreads risk, but you’ll need to make sure you can manage the repayments or equity commitments

• The right choice depends on your goals, risk tolerance, and how quickly you need to act

Photo by Mina Rad on Unsplash