A Reddit post recently surfaced a problem that sounds bizarre until you understand how HMRC’s address records work: a woman who has lived in England for 25 years received a tax code notice showing her code had changed from 1263L to S1263L — the S prefix meaning HMRC now classifies her as a Scottish taxpayer. When she logged into her Personal Tax Account for the first time, her main address was listed as one in Aberdeen, where she lived briefly nearly 30 years ago. Her actual English address was filed as a “postal address.”
She’d claimed tax credits and Universal Credit, held at least three jobs in England, and never moved back to Scotland. How did HMRC still think she lived in Aberdeen?
The answer is a combination of how HMRC receives address updates, how Scottish taxpayer status is determined, and a system that can overwrite a correct address with a stale one from a third party. Here’s what the S prefix means, how this happens, what it costs you, and how to fix it.
What the S Prefix Actually Means
Since 6 April 2016, HMRC adds an S prefix to the tax code of anyone it classifies as a Scottish taxpayer. So 1263L (standard English code) becomes S1263L (Scottish equivalent). The number part works the same way — 1263 × 10 = £12,630 tax-free allowance — but the rates and bands applied to your income above that allowance are different.
According to HMRC’s PAYE Manual (PAYE100035), Scottish taxpayer status applies where someone is UK resident and has their sole or main place of residence in Scotland for more of the tax year than in any other part of the UK. The status applies for a whole tax year — you can’t be a Scottish taxpayer for part of a year.
HMRC’s system (the National PAYE Service, or NPS) sets a “Scottish Taxpayer (STp) Status” signal on your record when it determines you’re Scottish. That signal is what triggers the S prefix on your code. The signal and your address are maintained separately — which is relevant when we get to fixing it.
What determines Scottish taxpayer status
The Scottish Taxpayer Technical Guidance (STTG4300) sets out the tests:
- Single place of residence: If you have one home and it’s in Scotland, you’re a Scottish taxpayer. If it’s in England, you’re not.
- Multiple places of residence: If you have homes in more than one part of the UK, you’re a Scottish taxpayer if your main place of residence was in Scotland for at least as long as it was in any other single part of the UK (STTG4400).
Crucially, where you work is not relevant. Where your employer is based is not relevant. Where your pension comes from is not relevant. Only where you live. As the guidance puts it: “The location of an individual’s employer or where they work is not relevant to deciding Scottish taxpayer status.”
So the Reddit poster’s wife — living in England for 25 years, working in England — should never have been classified as Scottish. The classification was driven entirely by the stale Aberdeen address on her record.
How a 30-Year-Old Address Resurfaces
This is the part that baffles people. She’s had three jobs in England, claimed tax credits and UC, updated her address with DWP — surely HMRC should know where she lives?
The mechanism is explained in HMRC’s PAYE Manual (PAYE103025), and it’s where the problem originates:
“With effect from April 2015 HMRC will automatically process any changes to existing employee’s addresses when an address update has been included on a Full Payment Submission (FPS).”
A Full Payment Submission is the payroll report your employer sends HMRC every time you’re paid. If your employer holds an old address for you and includes it on the FPS, HMRC’s system can automatically update your record with that old address — overwriting whatever was there before.
The same principle applies to data from DWP. As one Reddit commenter correctly noted: “It can happen if an employer/pension provider or the DWP send across pay info with that as her address.” If a DWP system (Universal Credit, tax credits, state pension) holds an old address and syncs it to HMRC, the old address can land on your tax record.
Here’s how the Aberdeen address likely survived for 30 years:
- She registered with HMRC in the 1990s using her Aberdeen address. This became the “base” address on her record.
- Subsequent address changes were layered on top — through jobs, tax credits, UC — but the system may have maintained the original as the “main” address and treated newer ones as postal/correspondence addresses. This matches what she saw: Aberdeen as main, England as “postal address.”
- An employer or DWP submission sent the Aberdeen address on a FPS or data sync, and HMRC’s system processed it automatically, reinforcing the Aberdeen record.
- The system recalculated her taxpayer status based on the Aberdeen address and set the STp signal to Scottish, flipping her code to S1263L.
The PAYE manual confirms the recalculation step: “When an address is changed from England or Northern Ireland to a Scottish or Welsh address or vice-versa, a calculation will be made to ensure the taxpayer status is still correct. The status of the taxpayer may change.”
So the address wasn’t a harmless error — it directly triggered the tax code change. And because the system processes employer/DWP address updates automatically, it can happen without you ever being notified until the tax code notice arrives.
What It Costs You: Scottish vs English Income Tax
Being on an S-prefix code when you shouldn’t be means you’re paying Scottish income tax rates instead of English ones. Whether that costs you more or less depends on your income level — but for most middle and higher earners, it costs more.
Scotland has six bands instead of England’s three. For 2025-26:
| Band | Scotland rate | Scotland income range | England rate | England income range |
|---|---|---|---|---|
| Personal Allowance | 0% | £0–£12,570 | 0% | £0–£12,570 |
| Starter | 19% | £12,571–£15,397 | — | — |
| Basic | 20% | £15,398–£27,491 | 20% | £12,571–£50,270 |
| Intermediate | 21% | £27,492–£43,662 | — | — |
| Higher | 42% | £43,663–£75,000 | 40% | £50,271–£125,140 |
| Advanced | 45% | £75,001–£125,140 | — | — |
| Top | 48% | Over £125,140 | 45% | Over £125,140 |
The crossover point is around £30,000–£36,000. Below that, Scottish taxpayers pay marginally less (thanks to the 19% starter rate). Above that, they pay progressively more, and the gap widens sharply:
| Salary | England tax | Scotland tax | Difference |
|---|---|---|---|
| £25,000 | £2,486 | £2,392 | Scotland £94 less |
| £35,000 | £4,486 | £4,477 | Roughly equal |
| £45,000 | £6,486 | £7,074 | Scotland £588 more |
| £50,000 | £7,486 | £9,174 | Scotland £1,688 more |
| £60,000 | £11,432 | £13,374 | Scotland £1,942 more |
| £75,000 | £17,432 | £19,674 | Scotland £2,242 more |
The biggest single driver is Scotland’s 42% higher rate kicking in at £43,663 — nearly £6,600 earlier than England’s 40% rate at £50,270. That’s a band of income where Scottish taxpayers pay more than double the English rate.
If the Reddit poster’s wife earns above ~£43,000 and has been on an S-prefix code, she’s likely been overpaying tax. The amount depends on her exact salary and how long the wrong code has been in place. The good news: once corrected, HMRC should recalculate and refund the overpayment.
How to Fix It
Step 1: Check your address in your Personal Tax Account
Log into your Personal Tax Account and look at the address on file. If it’s wrong — showing an old address, showing your current address as a “postal address” while an old one is “main” — you need to correct it.
Use HMRC’s change of address service to update your address. This updates it across your tax records.
Step 2: Check your tax code
While you’re in your Personal Tax Account, go to “Check your Income Tax” and look at your current tax code. If it starts with S and you live in England, Wales, or Northern Ireland, it’s wrong.
Step 3: Contact HMRC to correct your residency status specifically
This is the step many people miss. Updating your address should trigger a recalculation of your taxpayer status — but the STp signal and your address are maintained separately on HMRC’s system, and the address update alone doesn’t always clear the Scottish status.
As one Reddit commenter bluntly put it: “They don’t [auto-update]. You need to update HMRC. Give them a call and ask them to change residency.”
Call HMRC and specifically ask them to:
- Correct your main place of residence address (not just your postal address)
- Review and correct your Scottish taxpayer status — ask them to confirm the STp signal is being removed
- Issue a corrected tax code without the S prefix
HMRC’s Self Assessment Manual (SAM101380) notes that “Only HMRC can decide an individual’s customer status. An employer cannot make this decision or inform HMRC of an employee’s customer status” — so this is not something your employer can fix for you. It has to go through HMRC directly.
Step 4: Ask about the address history
The Reddit poster’s husband noted: “If you call HMRC each address change is dated so they may be able to confirm to you when and what prompted your address changes.”
This is worth doing. Ask HMRC to tell you:
- When the Aberdeen address was set as your main address
- What submission triggered the most recent update (employer name, DWP department, date)
- Whether any other stale data on your record might cause it to happen again
Knowing the source helps you prevent a recurrence — for example, if an old employer’s payroll system is the culprit, you can contact them to update their records.
Step 5: Check for overpaid tax
Once your residency status is corrected, ask HMRC to recalculate your tax for the affected year(s). If you’ve been on an S-prefix code while living in England and earning above ~£43,000, you’ve likely overpaid. HMRC should issue a P800 calculation or adjust your Self Assessment, and refund the difference.
If you’re due a refund and HMRC doesn’t automatically issue one, you can claim it. The normal deadline for claiming a tax refund is 4 years after the end of the relevant tax year.
How to Prevent It Happening Again
- Check your Personal Tax Account once a year — treat it like checking your credit file. The address and tax code are the two things to verify.
- Make sure every employer has your current address. Since HMRC auto-processes address changes from FPS submissions, a wrong address at an old employer can overwrite a correct one at HMRC. If you leave a job, make sure their final payroll submission has your current address, not a historical one.
- Update your address with DWP separately — tax credits, Universal Credit, and state pension records can sync to HMRC. If DWP holds an old address, it can propagate.
- If you’ve ever lived in Scotland, this is worth checking even if you think your code is fine. The STp signal can persist silently — you might not notice until a code change notice arrives, by which point you may have been on the wrong rates for months.
The Bottom Line
- An S prefix means HMRC thinks you’re a Scottish taxpayer. It’s based on your main place of residence, not where you work or where your employer is.
- A stale address is the usual cause. HMRC auto-processes address updates from employer payroll submissions and DWP, and an old address — even from decades ago — can resurface and overwrite your current one.
- The financial impact depends on your income. Below ~£30k, Scottish rates are marginally lower. Above ~£43k, you’re paying more — potentially thousands more per year.
- Updating your address alone may not fix it. The Scottish taxpayer status signal is maintained separately from your address. Call HMRC and ask them to correct the residency status specifically.
- You can reclaim overpaid tax. Once corrected, HMRC should recalculate the affected years and refund any overpayment.
For the complete tax code guide — anatomy, emergency codes, P2 notices, and refund forms — see our tax code explained hub. For the other common tax code problem — benefit in kind adjustments quietly reducing your allowance — see our tax code checking guide. For more plain-English explanations of HMRC terms, browse the full jargon buster.