𝗦𝗻𝗲𝗮𝗸𝘆 𝗖𝗵𝗮𝗻𝗴𝗲 𝗶𝘀 𝗮 𝗕𝗹𝗼𝘄 𝗳𝗼𝗿 𝗦𝗶𝗱𝗲 𝗛𝘂𝘀𝘁𝗹𝗲𝘀

While the media spotlight was fixed firmly on the big, shiny Budget headlines, something far less glamorous—and far more concerning—was hiding in the small print. A subtle change coming into force in 2029 could hit employees with side hustles right where it hurts: in their cash flow.

What’s behind this? And why does it matter?

𝗧𝗵𝗲 𝗧𝗿𝘂𝘁𝗵 𝗔𝗯𝗼𝘂𝘁 𝘁𝗵𝗲 𝘀𝗼-𝗰𝗮𝗹𝗹𝗲𝗱 “𝗲𝗕𝗮𝘆 𝘁𝗮𝘅”

Side hustles have exploded in recent years—some out of passion, many out of necessity.

With rising living costs, people are using small businesses to keep their households afloat. And as this world has grown, so has HMRC’s interest.

There’s been a lot of noise about the “eBay tax,” but in reality, it isn’t a new tax at all. What is new is HMRC’s sharpened focus on collecting tax faster and more efficiently.

𝗛𝗼𝘄 𝘁𝗵𝗶𝗻𝗴𝘀 𝘄𝗼𝗿𝗸 𝗻𝗼𝘄

At present, if you’re employed and file a Self Assessment return for your side hustle, you can choose to have any balancing payment (up to £3,000) collected through your PAYE tax code—as long as:

• The amount is below £3,000

• You file your return by 30 December

But it’s optional. If you prefer, you can simply pay your tax in the normal Self Assessment deadlines.

𝗕𝘂𝘁 𝗳𝗿𝗼𝗺 𝟮𝟬𝟮𝟵, 𝗼𝗽𝘁𝗶𝗼𝗻𝗮𝗹 𝗯𝗲𝗰𝗼𝗺𝗲𝘀 𝗺𝗮𝗻𝗱𝗮𝘁𝗼𝗿𝘆

Starting in tax year 2029/30, HMRC will automatically:

• Collect your previous year’s underpayment via PAYE

• PLUS collect an estimate of your current year’s tax bill

This means employees with side hustles will effectively be paying tax earlier than someone whose entire income falls under Self Assessment.

𝗖𝗿𝗲𝗮𝘁𝗶𝗻𝗴 𝗮 𝘁𝘄𝗼-𝘁𝗶𝗲𝗿 𝘀𝘆𝘀𝘁𝗲𝗺

Two people could earn exactly the same amount, but depending on how they earn it, they may have very different tax payment dates.

This raises questions:

• Is this fair?

• Does this align with HMRC’s Charter to treat taxpayers equally?

• Will this create avoidable financial stress for small and seasonal businesses?

Many argue it will.

Seasonal traders especially—those who earn more at certain times of the year—may face serious cash-flow pressure if tax is taken before their busy months arrive.

𝗜𝘀 𝘁𝗵𝗶𝘀 𝗮 𝗽𝗿𝗲-𝗲𝗺𝗽𝘁𝗶𝗻𝗴 𝗽𝘂𝘀𝗵 𝘁𝗼 𝗠𝗧𝗗?

A consultation is planned for 2026, and while that sounds like an opportunity for sensible discussion, some fear the direction of travel.

A cynic might reasonably wonder whether this becomes a lever to push more small businesses into Making Tax Digital, perhaps even making quarterly updates the only reliable way to keep PAYE codes accurate in real time.

Let’s hope it doesn’t come to that.

If this change concerns you, do what my clients do: Ask Brian.

Understanding these rules early helps you protect your cash flow, avoid surprises, and plan with confidence.

If you’re unsure how the 2029 change affects your side hustle or employment income…