Is my data private?
Yes, 100% private. All data processing happens in your browser — your files never leave your device. No servers, no databases, no third parties can access your data.
100% private · GDPR compliant · No uploads
Clean UK data in your browser
Phone numbers, postcodes, NI numbers, sort codes — validated instantly. Your data never leaves your device.
7-day free trial · No card required · View pricing
Sound familiar?
Phone numbers in every format. Postcodes with no spaces. NI numbers in lowercase. One export from your CRM, another from a survey — same data, five different styles. Manually fixing it means find-and-replace, copy-paste, and hoping you didn’t miss a typo.
Another cloud tool?
GDPR paperwork?
That’s why we built Simple Data Cleaner. Select your information and it validates, normalises, and formats everything to UK standards.
Phones, postcodes, NI numbers, sort codes, bank accounts, emails, names
Invalid rows flagged in a report
Runs in your browser — no uploads, no cloud, no paperwork
The Solution
Your data today
07700900461Mobile
sw1a1aaPostcode
ab123456cNI number
1.2.3.4.5.6Sort code
12345678Bank account
user@example.com Email
dr john smithName
And you can’t just upload this anywhere. Postcodes, NI numbers, customer details — it’s sensitive.
After Simple Data Cleaner
+44 7700 900461Mobile
SW1A 1AAPostcode
AB 12 34 56 CNI number
12-34-56Sort code
12 34 56 78Bank account
user@example.comEmail
Dr John SmithName
All in your browser. No uploads, no cloud, no risk.
A UK data cleaner built on official standards
Generic data cleansing tools guess. Simple Data Cleaner checks every field against the exact rules HMRC, Royal Mail, and Ofcom actually use for UK phone numbers, National Insurance numbers, postcodes, and sort codes.
UK-specific by design
Not a generic international data cleansing tool retrofitted for the UK - every rule is written against HMRC, Royal Mail, and Ofcom standards from the start.
Deterministic, not probabilistic
Every check is an exact rule, not an AI guess - so results are consistent every time. Why this matters more than AI.
An alternative to a consultant
For standard UK formats, get accurate results in minutes instead of a scoped engagement. Consultant vs. self-serve tool.
See the exact UK data cleansing rules we validate against.
How it works
Three steps. Your data never leaves your device.
100% in your browser
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Upload
CSV, Excel, or JSON. Your file stays on your computer.
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Select & clean
Pick columns (phone, NI, postcode, sort code, email, names). Auto-detect available.
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Download
Export CSV, Excel, or JSON. Full issues report included.
We validate
7 UK data types
Click one cleaned instantly
Phone numbers
NI numbers
Postcodes
Sort codes
Bank accounts
Emails
Name splitting
Try it now
Messy data in. Clean data out. Instant.
Phone
NI
Postcode
Sort code
Email
Result
—
100% in-browser. Nothing leaves your device.
What you should know
Everything you need in one place.
What UK data formats can I validate?
UK phone numbers (mobile and landline), National Insurance numbers, postcodes, bank sort codes and account numbers, email addresses, and name splitting. All validation follows official UK standards.
Is it GDPR compliant?
Yes. Because all processing happens in your browser, we are not a data processor under GDPR. Your data never leaves your device.
What file formats are supported?
Upload CSV, Excel (XLSX/XLS), or JSON. Export cleaned data in CSV, Excel, or JSON.
What you get when you upload
Beyond UK validation — duplicates, whitespace, export formats, and detailed reports. All in your browser.
Try it with sample data — no signup
Upload our pre-built test file and run through the full workflow. Validate UK data, see the issues report, preview cleaned results, and export — exactly what you'd get with your own files.
- Pre-loaded test file — phones, NI numbers, postcodes, and more
- Full HTML reports — issues, cleaned data preview, audit trail. See samples
- Export CSV or Excel — same output you'd get with your own data
