Cash inflow and outflow, simply explained

For many companies, tax season means stress. Not only do tax returns have to be filled out and sent in on time, but the HMRC also needs an accurate overview of all of your company’s operating income and expenses in order to determine the amount of your tax payment. Small companies, self-employed individuals, and freelancers can all use cash-basis accounting for this. The principles of cash inflow and outflow are described here. But what exactly do those principles mean, and how specifically are they applied?


Small businesses are generally free to choose between cash-basis accounting and accrual method of accounting. However, businesses with over £150,000 in turnover per year are required by the HMRC to use accrual accounting. This includes the turnover from all of your businesses, in case you run more than one - in which case, you also must use cash basis for all businesses. Companies too big for cash-basis accounting are encouraged to use double-entry accounting to help keep track of their finances. If your business grows to a turnover of up to £300,000 during the tax year, you can keep using cash basis, but must switch to a traditional method for the next year.

What does cash inflow and outflow mean?

Cash inflow and outflow play a decisive role in cash-basis accounting. To be able to submit your annual income to the HMRC properly, you need to record all company revenues and expenditures, and offset them against one another. This just means citing what your company has taken in and spent during the fiscal year. So, for this form of profit calculation, only the actual cash flow is taken into account. But what does that actually mean?

The revenues (inflow) and expenditures (outflow) are the sums that directly enter or exit the account. ‘Float’ amounts, i.e. money floating in the system between the two ends of a transaction (before being deposited in the recipient’s account or being deducted from the sender’s account), are not counted here. Just look at the sums that have been entered or taken out of your account at which time. This approach is the basis of the cash inflow and outflow principle.


The timing of the cash flow is the main aspect of the cash inflow and outflow principle. Which operational incomes and expenditures count toward the tax year and which don’t is decided by the date of the payment deposit or deduction.

Cash inflow principle

According to the HMRC, cash flow in the method of cash-basis accounting must record income in the tax year when the payment was received, regardless of when it was actually recorded in your books. An example of the cash inflow principle would be as follows:

You’re a fiscal year tax payer and have adopted your fiscal calendar to start in July of each year. You receive a payment on June 30, 2017 but you don’t enter it into your books until July 1, 2017, the start of the new fiscal year. While it can remain in the new fiscal year in your books (fiscal year 2018), it must be processed for tax reasons in the gross income for fiscal year 2017 – the year in which the payment was actually received.


Remember that credit card payments and transfers also count the actual date of the debit.

One point of interest is that the cash inflow doesn’t only decide the amount of your income, but also influences your tax bracket and how much you pay – the higher your income, the higher your bracket.


It’s worthwhile to record larger amounts of money at the end of the year for the following fiscal year. This allows you to keep your current profit margin low and pay fewer taxes.

Cash outflow principle

The cash outflow principle also uses the timing as a deciding factor for your profit calculation. Basically, it works just like cash inflow, but the timing of the actual payment is the decisive factor here. Expenses paid in advance are either counted toward the year in which they are applied, which can potentially split cash outflow across multiple tax years. Because payment date is so crucial for tracking cash outflow, it’s very important to keep all invoices and records of payment.


You can avoid most problems with VAT by making sure you deal with all the paperwork correctly. You may have to submit invoices and other documents to the HMRC. Make sure that you’re able to provide proper and complete accounting documents.

When it comes to cash outflow, there’s a special exception: depreciation, or the wear and tear of an asset (e.g. machines), may not be taxed for the full sum within one calendar year. The costs are instead distributed over several years, according to the uniform capitalization rules.

Please note the legal disclaimer relating to this article.

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