Paying Self Assessment Online in Cardiff: FAQ Answered for Local Drivers
Paying Self Assessment online is the quickest way to settle your tax bill, and Cardiff drivers can do it through their bank app, the HMRC app or a debit card using an 11-character reference. Payments are normally due by 31 January and 31 July, and this FAQ answers the questions Cardiff drivers ask most.
Published 9 October 2026 · Updated 9 October 2026
Paying Self Assessment online is the quickest way to settle your tax bill, and in Cardiff most drivers do it from their phone in a few minutes. You pay through your bank app, the HMRC app, or a debit card, using an 11-character payment reference. This FAQ answers the questions Cardiff drivers ask most about paying Self Assessment online.
It covers methods, timing, the reference, payments on account, Time to Pay and what changes if you live in Wales. For how your HMRC account works, see our guide to the HMRC online account for Cardiff drivers. Drivers elsewhere may prefer our guides for Liverpool or Birmingham.
Key takeaways
- Your balancing payment and first payment on account are normally due by 31 January, and the second payment on account by 31 July.
- Your payment reference is your 10-digit Unique Taxpayer Reference (UTR) followed by the letter K.
- Bank account approval is usually instant, but allow longer for Direct Debit: up to 5 working days the first time.
- Welsh residents pay the same combined 20%, 40% and 45% rates as England for 2026/27, but HMRC still needs to know you are a Welsh taxpayer.
- If you cannot pay in full, contact HMRC about a payment plan before the deadline, not after.
What is paying Self Assessment online?
Paying Self Assessment online means sending your income tax and Class 4 National Insurance bill to HMRC electronically, through your bank, the HMRC app or a debit card. HMRC records the payment on the day you make it, which gives drivers a quick, traceable alternative to cheques.
How do I pay my Self Assessment bill online?
The simplest route is to sign in to your HMRC online account or open the HMRC app, choose pay by bank account, and approve the payment in your own banking app. According to HMRC's guidance on approving a payment through your online bank account, it is usually instant but can take up to 2 hours to show in your bank.
The payee shown is HMRC Shipley. You can make more than one payment towards the same bill, and you can pick a future date as long as it falls before the deadline. That helps if you want to pay a little from each week's earnings. Always check your bank statement afterwards to confirm the payment left on the right day.
Step-by-step: paying by bank account approval
- Sign in to your HMRC online account, or open the HMRC app, and choose to pay your Self Assessment bill.
- Check the amount owed on your statement, then enter the amount you want to pay.
- Select the pay by bank account option and choose your bank.
- You are sent to your own banking app or website. Sign in there and approve the payment to HMRC Shipley.
- Wait for the confirmation screen, keep a screenshot, and check the money left your account on the correct day.
- Look at your HMRC statement a few days later to confirm the payment has been allocated to the right tax year.
A word on scams
HMRC will not ask you to pay through a link in an unexpected text or email. Start from GOV.UK or the HMRC app yourself. If a caller or message demands immediate payment by gift card or to a personal account, stop and check with HMRC using the contact details on GOV.UK. Fraudsters target busy drivers around January, when bills are large.
What are the different ways to pay Self Assessment?
HMRC accepts several methods, and each has a different clearing time. Bank account approval, Faster Payments, CHAPS and debit cards are the quickest. Bacs and Direct Debit take longer, and you can no longer pay at the Post Office. Choose a method that allows enough time before the deadline.
The table below uses processing times from HMRC's main guide to paying your Self Assessment tax bill. Always check the page itself before paying, because HMRC can change methods and timings.
| Method | Typical timing | Good for |
|---|---|---|
| Bank account approval (online or HMRC app) | Usually instant, up to 2 hours to show | Most drivers paying from a phone |
| Faster Payments (online or telephone banking) | Same or next day | Paying from your usual bank |
| CHAPS | Same or next day | Large, urgent bills |
| Personal debit card | Same or next day | Quick payment, no fee |
| Bacs | 3 working days | Planned payments |
| Direct Debit (set up before) | 3 working days | Regular, repeat payments |
| Direct Debit (first time) | 5 working days | Spreading the cost early |
For most Cardiff drivers the fastest and cheapest choice is bank account approval. It needs no card, has no fee and gives you an instant record. Direct Debit suits drivers who prefer a set-and-forget approach, but remember the five-day wait if you have never set one up with HMRC.
What is my Self Assessment payment reference?
Your payment reference is your 10-digit UTR followed by the letter K, making 11 characters. HMRC's guidance on paying by card says you can find it in your HMRC online account, or on your paying-in slip if you receive paper statements.
Enter it exactly. A wrong reference can delay a payment or send it to a different tax bill, and you may then have to ask HMRC to move it. If you use a banking app that wants a reference field, type the UTR plus K with no spaces. Never guess or reuse an old reference from a different tax type.
When is the deadline for paying Self Assessment?
The balancing payment for the previous tax year and your first payment on account are normally due by 31 January. The second payment on account is normally due by 31 July. For tax year 2025/26, the main payment date is 31 January 2027, so plan your cash a few weeks ahead.
If the date falls on a weekend or bank holiday, HMRC says the payment must arrive by the last working day before, except for Faster Payments and card payments. Our key tax dates for Uber drivers page lists every date in one place.
Does HMRC count the day I pay or the day it lands?
HMRC's card payment guidance states that it treats a card payment as made on the day you pay, even at weekends or bank holidays. Faster Payments work the same way. Slower methods such as Bacs depend on when the money arrives, which is why you should avoid them in the last week before 31 January.
How do payments on account work for Cardiff drivers?
Payments on account are advance payments towards your next tax bill. Each one is usually half of last year's bill, due on 31 January and 31 July. You normally need to make them unless last year's bill was under £1,000, or you paid more than 80% of your tax outside Self Assessment.
This catches many new drivers out, because the first Self Assessment bill can include your whole tax for the year plus the first payment on account. HMRC explains the rules in its guide to payments on account. If this is your first return, read our first tax return guide for new Uber drivers as well.
Can I reduce my payments on account?
Yes, if you expect to owe less tax than last year. HMRC says you can sign in, view your latest return and select the option to reduce payments on account, or send form SA303. If your final bill turns out higher than you estimated, HMRC charges interest on the difference, so be realistic about your earnings. Drivers whose income fell, for example after a period off the road, are the usual candidates.
What is the Welsh Rate of Income Tax and does it change how I pay?
The Welsh Rate of Income Tax is the Welsh part of income tax for people who live in Wales. For 2026/27 the combined rates are 20%, 40% and 45%, the same as England. It does not change how you pay, but you must tell HMRC you are a Welsh taxpayer on your return.
According to HMRC's guidance on Welsh income tax, you pay Welsh rates for a tax year if you live in Wales longer than anywhere else in the UK during that year. HMRC says the return has a box to tell it you pay Welsh rates. Savings interest and dividends are taxed at UK-wide rates.
In practice, a Cardiff driver on a self-employed profit sees the same percentage bands as a driver in Bristol. The difference is administrative: your record should carry the Welsh marker, and a mistake about your main home can mean the wrong rates are applied. If you moved to or from Wales during the year, take advice before you file.
Welsh residents who also have an employed job will see a C prefix on their tax code, such as C1257L. That is HMRC's way of applying Welsh rates through PAYE. It does not appear on your Self Assessment payment, which is simply a total of tax and National Insurance owed.
What can I do if I cannot pay my Self Assessment bill in full?
Contact HMRC as early as you can and ask about a payment plan, known as Time to Pay. HMRC says it may let you pay overdue tax in monthly instalments, but it will check the plan is affordable. If you cannot agree one, HMRC will ask for the full amount.
According to HMRC's guidance on paying a tax bill in instalments, you will need your UTR, your UK bank details so you can set up a Direct Debit, and details of your income and spending. HMRC also expects you to use savings to reduce the debt first. Online eligibility limits have changed over time, so check the current rules on that page.
Is there a way to pay in small amounts before the bill arrives?
Yes. A Budget Payment Plan lets you make weekly or monthly Direct Debit payments towards your next bill. HMRC's page on paying weekly or monthly says you must be up to date with your last bill, and you can pause payments for up to 6 months. If you overpay, you can ask for a refund.
Can I pay Self Assessment with a credit card?
You cannot pay Self Assessment with a personal credit card. HMRC accepts personal debit cards with no fee, and corporate cards with a non-refundable fee. If a card will not cover the full amount, use another method such as a bank transfer, and keep the HMRC payment confirmation for your records.
What happens if I pay late?
Late payment attracts interest, and HMRC may add a penalty. Late filing is separate: HMRC says you are charged £100 for missing the filing deadline, with further penalties if your return is more than 6 months late. The exact late-payment penalty percentages are set out in HMRC's guidance, so check the current figures on GOV.UK before relying on any number.
HMRC publishes its interest rates for late and early payments, and they change. If you are worried about a penalty you think is wrong, professional help is wise. Our HMRC support service handles that for drivers.
What local Cardiff factors affect a driver paying tax?
Cardiff drivers are licensed by Cardiff Council, which licenses both hackney carriage and private hire drivers. The costs of that licensing and your vehicle can be allowable expenses, which lowers the profit your tax bill is based on. Cardiff has also taken a different route on clean air from cities with charging zones.
Only Cardiff-licensed hackney carriages can be hailed or picked up from a rank. Private hire drivers need a prior booking through a licensed operator. According to published council material, a driver licence can run for a maximum of three years, with fresh checks on renewal. Fees and conditions change, so check the Cardiff Council licensing pages for the current position.
On air quality, news reports from around 2019 say Cardiff Council chose not to introduce a charging Clean Air Zone, and instead planned non-charging measures such as cleaner buses and taxis and city centre traffic changes. In 2023 the council also discussed a possible low-cost road user payment. Rules can change, so check the council's Clean Air Cardiff pages before you assume there is no charge.
For a driver, the tax point is simple. Keep receipts for licence fees, vehicle checks and any emission-related upgrades. Our guide to allowable expenses for Uber drivers shows what counts, and the tax calculator gives you a rough bill to save towards.
How should Cardiff drivers set aside money for the bill?
Set aside a fixed share of each week's profit in a separate savings account so the 31 January bill does not surprise you. Use the tax calculator for an estimate, then move that money weekly. Remember that your first payment on account makes the January total larger than one year's tax. The checklist below keeps it simple.
- Open a separate savings pot used only for tax, and move money in every week.
- Update your estimate each quarter as your earnings change.
- Keep your mileage log and receipts organised, as covered in our guide to HMRC mileage log records.
- Log in to your HMRC account in December to check the amount and the reference.
- Pay early if you can, and use a dated payment to lock in the date.
Drivers registering for VAT or planning digital record keeping have extra dates to watch. Our guides to Self Assessment and VAT and Making Tax Digital explain how those fit around your January payment.
Common mistakes when paying Self Assessment online
Most problems are avoidable. The table shows frequent mistakes and what each can trigger. Penalty figures change, so confirm them on GOV.UK. This list covers payment errors only; return mistakes carry their own penalties and are best handled with professional help.
| Mistake | What can happen |
|---|---|
| Paying on the deadline using a slow method such as Bacs | Payment arrives late, so interest and possibly a penalty |
| Using the wrong reference or leaving off the K | Payment delayed or applied to another bill |
| Trying to pay with a personal credit card | Payment refused, so you may miss the date |
| Ignoring payments on account | A larger-than-expected January bill and cash-flow trouble |
| Not telling HMRC you are a Welsh taxpayer | The wrong rates may be applied |
| Waiting until after the deadline to ask for help | Interest and penalties build up before a payment plan starts |
Key terms
- UTR: Unique Taxpayer Reference, the 10-digit number HMRC gives you for Self Assessment.
- POA: payment on account, an advance payment towards next year's bill.
- Balancing payment: the difference between your final bill and payments already made.
- Time to Pay: an HMRC arrangement to pay an overdue bill in instalments.
- NIC: National Insurance contributions, including Class 4 for the self-employed.
- WRIT: the Welsh Rate of Income Tax.
How UK Driver Accountants helps
UK Driver Accountants is an independent UK accountancy for Uber, Bolt and private hire drivers, with fixed fees from £20 a month. We work out your bill, tell you exactly what to pay and when, and file your return. We are not part of Uber or Bolt. See our personal tax service and pricing.
Cardiff drivers can find local details on our Cardiff page. For a wider look at your return, read our Cardiff Uber driver tax return update, or compare approaches in Self Assessment vs Making Tax Digital.
Pay on time and stay in control of your tax
Paying Self Assessment online is quick once you know your reference, your deadline and your payments on account. Plan early, choose a fast method and ask HMRC for help before a payment is late. If you would rather hand it over, contact us and we will tell you what to pay.
Last reviewed 9 October 2026 by the UK Driver Accountants tax team.
This article is general information and is not personal tax advice. Speak to a qualified accountant about your own circumstances. If HMRC disputes a payment or charges a penalty, professional representation is recommended.
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