Best Bank Accounts for Part-Time Sole Traders UK 2026

Working 9–5 but running a side business?

Here's the problem: most business bank account guides assume you're full-time. They recommend accounts with 30+ free transactions per month and invoice features built for people sending dozens of invoices. But if you're an employed teacher who tutors on weekends, or a developer who freelances 5 hours a week in the evening, you have a very different set of needs.

You might do 5–12 transactions per month. You probably send 1–4 invoices. You definitely don't need a £15/month account with features you'll never use. You need something free, simple, and specifically suited to low-volume self-employment alongside a full-time job.

I spent several months in exactly this situation — running part-time consultancy work alongside a full-time role — and tested four accounts during that period. Here's what I found.

Quick answer: For most part-time sole traders, Mettle by NatWest is the best account. It's permanently free, includes 20 transactions per month (enough for most side hustles), and comes with a free FreeAgent accounting subscription that handles your Self Assessment automatically. For those doing even fewer transactions (under 10/month), Starling has no transaction limits and is free forever — arguably even simpler.

What Part-Time Sole Traders Actually Need From a Bank Account

This is different from what a full-time business owner needs. Let me be specific.

Low or zero transaction costs. You're not processing 50 payments a month. A part-time tutor might receive 8 parent payments per month and make 3 software subscription payments. That's 11 transactions. You need an account where 11 transactions costs you nothing.

Simple tax handling. The biggest administrative challenge for part-time sole traders is the Self Assessment tax return — specifically, calculating your self-employment income and allowable expenses when you've been employed all year at the same time. Accounts that automatically categorise expenses and calculate rough tax liability are genuinely useful here.

Low or no monthly fee. If you're earning £6,000/year from your side work, a £12/month banking fee represents 2.4% of gross income. That's £144/year for something you should be getting for free.

No minimum transaction requirements. Some business accounts effectively require active use to remain open (a minimum number of transactions or minimum monthly balance). That's problematic for a part-time business that might have quiet months.

Easy access without dedicated time. You're employed full-time, so you don't have 30 minutes during business hours to sort out banking on the phone. Accounts that are fully manageable via app — at 10pm if that's when you have time — are a meaningful practical advantage.

Best Accounts for Part-Time Sole Traders

Mettle by NatWest: My Top Pick for Part-Time Sole Traders

Mettle is genuinely designed for exactly this use case. The NatWest team that built it has been explicit about targeting "self-employed individuals with relatively low transaction volumes" — which is precisely what a part-time sole trader is.

The free FreeAgent subscription is the differentiator. FreeAgent is accounting software that costs £19/month if you pay separately — that's £228/year. With Mettle, it's free as long as your account is open. For a part-time sole trader earning £8,000/year from their side work, that's almost 3% of annual income saved on software alone.

FreeAgent handles:

• Income and expense tracking (synced directly from your Mettle account)
• Self Assessment tax return preparation and direct HMRC filing
• Invoice creation and sending
• Mileage tracking
• Real-time tax liability estimate

For someone doing a Self Assessment return for the first time (mixing employment income with self-employment income), FreeAgent's guided process is genuinely reassuring. It tells you what information to enter, walks you through allowable expense categories, and files directly to HMRC. The £228/year free software saving effectively means Mettle pays you to use it rather than the other way around.

The 20 transaction limit per month is the relevant constraint. Let's put it in real terms:

A part-time freelance copywriter taking on 3 clients per month typically does:

• 3 client payments received
• Grammarly subscription (1)
• Stock photography subscription (1)
• Relevant book purchase (1)
• Occasional train to a client meeting (1–2)

That's 7–9 transactions per month. Well within Mettle's 20 free. Even with some months being busier, it's unlikely a part-time sole trader crosses 20 regularly.

Should You Tell Your Employer About Your Side Business?

This comes up often, and the answer is: it depends entirely on your employment contract.

Most employment contracts contain one or more of these clauses:

Secondary employment clause: Requires you to notify your employer if you take on any other paid work. Common in public sector jobs and financial services. Usually requires approval, not just notification. Check your contract carefully.

Conflict of interest clause: Prohibits work that competes with your employer's business or clients. A marketing professional at an agency who freelances for the agency's competitors has a clear conflict. A teacher who tutors subjects unrelated to their school's curriculum typically doesn't.

IP assignment clause: Some contracts claim ownership of any intellectual property you create during your employment period, even on personal time. This is less common but can affect writers, software developers, or designers. If your side work involves creating original content or code, check this carefully.

The practical guidance: read your contract, and if you're unsure, ask HR for clarification in general terms ("I'm thinking about some evening freelance work unrelated to my role here — is there anything in my contract I should be aware of?"). Most employers don't object to genuinely unrelated evening work. Many actively don't care.

Tax: How It Works When You're Employed AND Self-Employed

This is the part most part-time sole traders get confused about, and understandably so. You have two income streams — employment income (taxed at source through PAYE) and self-employment income (which you declare through Self Assessment).

Here's how it works in practice:

Your Personal Allowance is shared. The £12,570 Personal Allowance (2025/26 tax year) applies to your total income. If you earn £28,000 from employment, you've already used your full personal allowance through PAYE. Your self-employment profit is taxed from the first pound at the basic rate (20%).

You must register for Self Assessment. If your self-employment income exceeds £1,000 in a tax year (which starts 6 April), you must register with HMRC and file a Self Assessment return by 31 January following the end of that tax year. HMRC has been increasing enforcement of this — don't assume a side income is too small to matter.

National Insurance applies to profit above £12,570. But since your employment income likely already exceeds this, your self-employment profit is subject to Class 4 NI from the first pound of profit. For the 2025/26 tax year, Class 4 NI is 6% on profits between £12,570 and £50,270, and 2% above that.

Set aside 25–35% of every payment. The exact amount depends on your income and tax band, but a 30% buffer is a reasonable starting rule. Move that 30% to a separate savings pot or account every time a client pays you. Starling's tax pots automate this.

The single most important thing a part-time sole trader can do is open a Self Assessment online account with HMRC and register as self-employed before the October 5 deadline in the year after you start trading. Leave this too long and you'll face late registration penalties on top of the tax itself.

Allowable Expenses for Part-Time Sole Traders

This is where a clean business bank account pays dividends (literally). Allowable expenses reduce your taxable profit, which reduces your tax and NI bill. But you need to document them clearly.

Common allowable expenses for part-time sole traders include:

• Home office costs: A proportion of heating, electricity, and broadband if you work from home (simplified flat rate: £6/week for 25+ hours/month working from home)
• Phone bill: The business-use proportion of your mobile contract
• Software subscriptions: Anything you use for your self-employment work (Adobe, Canva, Grammarly, accounting software, etc.)
• Professional development: Books, courses, and training directly related to your self-employed work
• Travel: Getting to client meetings (keep a log; Mettle's FreeAgent handles mileage)
• Professional subscriptions: Membership of trade or professional bodies relevant to your work
• Equipment: A proportion of laptop, camera, or other equipment used for self-employment

A separate business account means all of these flow through one place, are categorised automatically, and form a clean record if HMRC ever queries your return. Without a separate account, you're trying to identify business expenses from months of mixed personal and business spending — slow, error-prone, and likely to result in missed deductions.

Do You Need Invoicing Software as a Part-Timer?

Probably not a standalone paid product. Here's the honest answer for different scenarios:

1–4 invoices per month: The invoice generator built into Tide or the FreeAgent software you get free with Mettle is more than adequate. Both create professional invoices, allow custom branding, and track payment status. No additional software needed.

5–10 invoices per month: Mettle's free FreeAgent becomes quite valuable at this volume — it tracks which invoices are outstanding, sends automated reminders, and maintains an AR ledger. Still free with Mettle.

10+ invoices per month: At this volume, you're arguably not "part-time" anymore in terms of administrative overhead. Xero (from £14/month) or QuickBooks (from £12/month) are worth considering — both integrate with Starling or Tide via Open Banking.

For most part-time sole traders, Mettle + FreeAgent gives you everything you need for invoicing without paying anything extra for it.

When to Switch From a "Part-Time" to a "Full Business" Account

There's no formal category of "part-time sole trader account" — any business account works. But there are signals that you've outgrown a low-volume account:

• Regularly exceeding 20 free transactions per month — if you're consistently paying for extras with Mettle or Monzo, upgrade to somewhere unlimited (Starling, Anna)
• Self-employment income approaching £50,000 — at this level, tax complexity increases significantly and you should work with an accountant
• Thinking about going full-time — at the point of leaving employment, revisit your banking setup with the needs of a full-time business in mind
• VAT registration threshold (£90,000) — if your part-time side income is approaching this, you almost certainly need to reclassify it as full-time work and get a more capable account

Handling Cash as a Part-Time Sole Trader

Some part-time sole traders regularly receive cash: tutors, dog walkers, market stallholders, cleaning services, and tradespeople doing small local jobs. If that's you, digital-only accounts create a friction point.

Starling allows free cash deposits at any Post Office — your nearest Post Office is the deposit point. That works for cash income up to a few hundred pounds per week without expense.

Mettle charges £1 per Post Office cash deposit — acceptable for occasional cash, less ideal if you're regularly depositing large sums.

High street banks (Lloyds, NatWest, Barclays) have branches for cash deposits, which may be more convenient if you're in an area with limited Post Offices. Their free intro periods (12–30 months) make them a reasonable choice for cash-heavy part-timers.

Frequently Asked Questions

Do part-time sole traders need a business bank account?

No legal requirement — but practically, yes. Even 2–3 client payments a month, mixed with personal spending, makes Self Assessment genuinely difficult. Free accounts like Mettle and Starling cost nothing and make tax time much easier. Use one.

Do I tell my employer about my side business?

Check your employment contract first. Many include secondary employment or conflict-of-interest clauses. Most employers have no objection to genuinely unrelated freelance work in your own time, but get clarity from HR or your contract before starting rather than after.

How much can I earn before paying tax on my side income?

You can earn up to £1,000 from self-employment under the Trading Allowance without reporting it. Above £1,000, register for Self Assessment. Your self-employment profit is added to your employment income and taxed at your marginal rate — for most part-timers already earning above the Personal Allowance from their job, that means 20–40% Income Tax plus Class 4 National Insurance on self-employment profit.

What's the best account for a part-time tutor with 8 client payments per month?

Mettle is perfect: 8 payments in, 3–4 expense transactions out = well within 20 free transactions. Permanently free. Free FreeAgent handles your invoices and Self Assessment. What more do you need?

Can I apply for a business account while still employed?

Yes, absolutely. Being employed does not prevent you from opening a business account or registering as self-employed. Banks don't cross-check with your employer. You simply open the account in your own name (as sole trader), describe your side business, and you're done.

My Recommendation for Part-Time Sole Traders

Open a Mettle account this week. It takes about 15 minutes. It's free forever. The FreeAgent subscription it includes will handle your Self Assessment, which is the single thing most part-time sole traders dread most about running a side business.

If you'd prefer no transaction limits at all (so you never think about it), open Starling instead. Also free forever. The slightly better alternative if your transaction volume sometimes spikes unpredictably.

Either way: the single most important thing you can do for your part-time side business finances is separate the money from your personal account. Open the account today.

Related guides:

• Best Free Business Bank Accounts UK: 12 Compared
• Best Business Bank Accounts for Sole Traders
• How to File Your Self Assessment Return
• National Insurance for the Self-Employed
• Self-Employment Hub

Last updated: February 22, 2026. All fee information sourced from provider websites at the time of writing. Always verify current terms directly with providers before applying. This article is for informational purposes and does not constitute financial or tax advice.