Payments on Account: Why Your Tax Bill Can Feel Higher Than Expected
For many individuals in Self Assessment, one of the biggest shocks isn’t the tax bill itself — it’s the amount due in January. People often expect to pay tax once a year, only to find that the figure is far higher than anticipated, even when income hasn’t increased dramatically.
In most cases, this isn’t an error. It’s the result of payments on account, a system that catches many people out because it’s poorly understood and rarely explained clearly at the outset.
Understanding how payments on account work — and why they exist — can remove much of the confusion and help avoid unpleasant surprises.
What are payments on account?
Payments on account are advance payments towards your next tax bill. Rather than waiting until the following January to collect all the tax due, HMRC requires certain taxpayers to pay part of it early.
They usually apply if:
- You are in Self Assessment, and
- Your tax bill exceeds a minimum threshold, and
- Less than most of your tax is collected at source (for example through PAYE)
If payments on account apply, HMRC effectively assumes that your income will be similar to the previous year and asks you to pay tax in advance on that basis.
Why January bills often include two amounts
When payments on account apply, the January bill typically includes:
-
The balancing payment for the tax year just ended, and
-
The first payment on account for the following tax year.
Each payment on account is usually 50% of the previous year’s tax bill, with the second instalment due the following July.
This is why a January bill can feel disproportionately large — it often includes tax for two different years rolled into one figure.
Why income changes make things confusing
Payments on account are based on the assumption that income remains broadly the same from year to year. When that assumption doesn’t hold, confusion and frustration often follow.
Common situations include:
- Income falling but payments remaining high
- A one-off high-income year inflating future payments
- Changes in employment or business activity
- Rental income starting or stopping
In these cases, payments on account may no longer reflect reality.
Can payments on account be reduced?
In some circumstances, payments on account can be reduced if it’s clear that your income — and therefore your tax bill — will be lower.
However, this needs to be approached carefully. Reducing payments too aggressively can lead to:
- Interest charges
- Underpayment issues
- Further adjustments later on
This is an area where clarity matters more than speed. Reductions should be based on realistic expectations rather than optimism.
Cash flow is often the real issue
For many people, the challenge with payments on account isn’t the total tax paid, but when it’s paid.
Paying tax earlier than expected can:
- Strain cash flow
- Affect savings or borrowing
- Create stress around deadlines
Understanding the timing allows for better preparation, even when the total tax bill itself is unavoidable.
New to Self Assessment? Expect payments on account
People entering Self Assessment for the first time are often unaware that payments on account will apply at all. The first year can therefore feel particularly heavy, as it includes:
- Tax for the first year of reporting, and
- Advance payments for the next year.
Knowing this early helps set expectations and avoid surprise.
When payments on account stop
Payments on account don’t apply forever. They may stop if:
- Income falls below certain levels
- More tax is collected at source
- You leave Self Assessment altogether
However, HMRC doesn’t always automatically remove them immediately, which is why periodic reviews are useful.
Payments on account as part of wider planning
Rather than treating payments on account as an unavoidable nuisance, they are best seen as part of the broader tax picture.
When reviewed alongside:
- Current income levels
- Expected changes
- Cash flow needs
- Other tax obligations
They become far more predictable and manageable.
Avoiding repeated surprises
The most common frustration around payments on account is not paying tax itself, but repeatedly being surprised by the amounts due.
Once the system is properly understood and reviewed regularly, those surprises usually disappear. What remains is a clearer sense of what to expect and when.
Payments on account are one of the most misunderstood aspects of the tax system, yet they affect a wide range of individuals — from the self-employed to landlords and those with multiple income sources.
If you’d like to understand how payments on account apply to you, whether they can be adjusted, or how to plan for them more effectively, you can book a free 30-minute call to talk through your position and get clear, practical guidance tailored to your circumstances.
