Published: 14/01/2026 By Hannah Duncan
As the self-assessment deadline approaches, many sole traders and small business owners find themselves facing an uncomfortable position: the tax bill is due, but the money isn’t readily available.While it can feel overwhelming, falling short on a tax payment is far more common than people realise. What matters most is how you respond. Acting early and methodically can prevent short-term pressure from turning into a longer-term problem.
If you’re concerned you won’t be able to pay your self-assessment bill in full by 31st January, here are some sensible steps to take.
Start with clarity, not assumptions
Before making any decisions, make sure you’re working with the correct figures, it sounds silly but small mistakes can add up. Check the final amount due and ensure you understand what it relates to, particularly if your bill includes payments on account for the year ahead, which can catch people out. Having a clear, confirmed amount allows you to plan properly rather than reacting based on estimates or worst-case scenarios.
Review your return carefully
Errors on self-assessment returns are more common than many expect, especially when they’ve been completed in a rush. Reviewing income figures, expenses and reliefs can sometimes reveal mistakes that artificially inflate the amount owed. Taking the time to sense-check your return before paying can save you from unnecessary financial strain.
Make a payment, even if it’s partial
If paying the full balance isn’t possible, consider paying what you reasonably can. A partial payment reduces the outstanding amount and demonstrates engagement, which is always preferable to doing nothing. It also helps turn an intimidating lump sum into a more manageable situation.
Seek professional support sooner rather than later
Tax problems are far easier to deal with when there’s time. Speaking to an accountant early opens up more options and gives you space to make informed decisions, rather than scrambling under deadline pressure. Good advice at the right moment can help you protect cashflow and avoid avoidable penalties.
Communicate with HMRC
Avoiding contact rarely ends well. If you know you can’t pay what’s due, it’s usually better to tell HMRC in advance rather than waiting until the deadline has passed.
In many cases, HMRC may be willing to agree a Time to Pay arrangement, allowing you to spread the cost over affordable instalments based on your circumstances.