Dashboard
Every check you need. Sorted in seconds.
Bank details, IDs, companies, securities and more. Type or paste below and get a straight answer, plus exactly what’s wrong if something’s off.
Click the ☆ on any tile to pin it here.
IBAN checker
Checks the country's IBAN length, the structure, and the mod-97 check digits.
Try: , , ,
Don’t have the IBAN?
Results appear as you type.
BIC / SWIFT checker
Checks the structure (bank, country, location and branch) and the country code.
Try: , ,
Results appear as you type.
Suggestions come from SmugPuffin’s built-in list of major banks and need no internet. 🌐 “Search all banks” sends the name you typed to the official GLEIF register.
UK sort code & account number
Checks a sort code on its own, or runs the real VocaLink modulus check (spec v8‑50) used by UK banks once you add the account number.
Try a valid pair: , or an invalid one:
Tip: paste a sort code and account number in any format, like 20-00-00 55779911, and it fills both boxes.
Enter a sort code to check it, then the account number for the full bank check.
UK VAT number checker
Runs HMRC's published mod-97 check-digit calculation, plus the government department (GD) and health authority (HA) formats.
Try: , ,
Results appear as you type.
Payment card number checker
Runs the Luhn checksum used by every major card network, and identifies the likely network from the prefix.
Try: , ,
Results appear as you type.
ISIN checker
Checks the format and the Luhn check digit.
Try: , ,
Results appear as you type.
CUSIP checker
Checks the format and the check digit.
Try: ,
Results appear as you type.
SEDOL checker
Checks the format and the check digit.
Try: ,
Results appear as you type.
LEI checker
Find a company’s LEI by name, or check an LEI’s format and check digits, then look it up live in the official GLEIF register.
🌐 Searching sends the name you typed to the official GLEIF register. Press Search or Enter.
Try: ,
Results appear as you type.
Companies House
Type a company number to check its format and jump straight to that company on the official register, or type a name to search for it there.
Try: , , ,
Results appear as you type.
National Insurance number checker
Checks the published format rules: excluded letters, excluded prefixes and the final letter.
Try: , ,
Results appear as you type.
Passport number checker
Runs the ICAO 9303 check digit used in every passport's machine-readable zone. Works for any country's passport, not just the UK's.
Try the ICAO worked example: , ,
Results appear as you type.
Enter just the printed passport number and this can only confirm the shape, not the checksum. Paste the 9-character MRZ number plus its check digit (10 characters) for a real check.
UK driving licence number
DVLA has never published a checksum for this number, so this decodes the embedded date of birth and sex for a plausibility check. It cannot confirm the licence is genuine.
Try: ,
Results appear as you type.
Vehicle Identification Number (VIN)
Runs the North American check-digit calculation, mandatory for vehicles sold there since 1981.
Try: ,
Results appear as you type.
This check digit is a North American requirement. Correctly formatted VINs issued elsewhere may not satisfy it.
UTR (Unique Taxpayer Reference)
Runs the widely-used advisory check-digit calculation. HMRC has never officially published this algorithm, so treat a mismatch as a prompt to double-check, not proof of an error.
Try: ,
Results appear as you type.
Employer PAYE reference
Checks the standard format: a 3-digit tax office number, a slash, then the employer reference.
Try: ,
Results appear as you type.
UK postcode checker
Checks the format instantly, then confirms the postcode really exists and shows its area, using official UK open data.
Try: , ,
Results appear as you type.
DBS certificate number
DBS has never published a checksum for this number, so this is a format check only. Always confirm the certificate itself at gov.uk/verify-dbs-check if it matters.
Try: ,
Results appear as you type.
Biometric Residence Permit number
BRP formats have varied over time and there's no public checksum. This is a loose shape check only, so always confirm via the official right to work check.
Try: ,
Results appear as you type.
Email domain check
Checks the email format as you type. Press the button to confirm the domain actually has mail servers, so you can catch a typo like "gmial.com" before it bounces.
Try: ,
Results appear as you type.
Passport & ID card reader
Paste the machine-readable lines (the rows of letters and < symbols) from a passport, ID card or BRP. Every check digit is verified using the international ICAO 9303 standard, and the name, nationality, dates and expiry are read out.
Try the official ICAO specimens: ,
Results appear as you paste.
Nothing you paste here leaves your browser.
IBAN calculator
Builds an IBAN, including its check digits, from domestic bank details. The result is run straight through the IBAN checker.
The bank code is the first four letters of the bank’s BIC/SWIFT code (for example NWBK). It can’t be worked out from the sort code, so take it from the bank or the payee.
Try: ,
Fill in the details to calculate the IBAN.
EU domestic account checks
Coming soon.
Not built yet. Each country has its own domestic bank code and account checksum rules. Germany alone has around ten. Rather than guess, these will be added one country at a time, each sourced from its published specification.
Planned order: Germany, France, Spain, Italy, Netherlands. Tell us which one you need first.
Check a list
Check a whole spreadsheet column at once. Coming soon in SmugPuffin Pro.
Coming soon in SmugPuffin Pro
Bulk checking, dozens or hundreds of rows at a time, is coming in SmugPuffin Pro: a single downloadable file with no installer and no admin rights needed, so it works even on a locked-down work machine.
Everything else on this site stays free: one-at-a-time checks for IBAN, BIC, UK accounts, securities IDs and LEIs, with no limit on how many times you use them.
IBAN length reference
Search by country name or code.
| Country | Code | IBAN length | Digits after country code & check digits |
|---|
Privacy notice
Last updated 11 October 2026
The short version: SmugPuffin doesn’t collect, store or sell your data. The checks run in your own browser, there are no accounts, and there are no cookies.
Who runs SmugPuffin
SmugPuffin (smugpuffin.com) is an independent website run from the United Kingdom. You can contact us at hello@smugpuffin.com.
What happens to what you type
Every check runs on your own device. What you type or paste, and any document you drop into Smart check, is not sent to us, logged or stored. You can confirm this yourself in your browser’s network tab.
The few things that are sent elsewhere
Some tools need to look something up in a public register. Each one is clearly marked and only runs when you press its button:
- LEI and BIC lookups, and bank and company name searches send what you typed to GLEIF, the official global LEI register.
- Postcode lookups send the postcode to postcodes.io.
- The email domain check sends only the part after the @ to Google Public DNS. The name before the @ never leaves your device.
- Companies House search opens the official Companies House website in a new tab, with the company name or number you typed.
Like any website, these services can see your IP address when your browser contacts them. Their own privacy policies apply.
What’s saved on your device
Your tile layout, favourites, light or dark theme and home timezone are saved in your browser’s local storage, so they’re still there next time. They stay on your device and are never sent to us. Clearing this site’s data in your browser removes them. We don’t use cookies or any tracking.
Visitor numbers
We count visits with Cloudflare Web Analytics, which doesn’t use cookies, doesn’t follow you around the web and doesn’t identify you. It tells us things like how many people visited and which tools are popular.
Hosting
The site is hosted by Cloudflare. Like any web host, Cloudflare handles basic technical information, such as your IP address, to deliver pages and protect the site from attacks.
Your rights
Because we don’t hold personal data about you, there’s usually nothing for us to show you or delete. If you email us, we’ll use your email only to reply. If you’re unhappy with how your data is handled, you can contact the Information Commissioner’s Office at ico.org.uk.
Changes
If anything here changes, we’ll update this page and the date at the top.
Terms of use
Last updated 11 October 2026
SmugPuffin is free to use. Please read these short terms, because they explain what the checks can and can’t tell you.
1. What SmugPuffin does
SmugPuffin checks the format and check digits of things like bank details, company numbers and ID numbers. A pass means the detail could be valid. It does not mean the account, company, person or document is real, active, or belongs to who it claims.
2. It isn’t verification or advice
SmugPuffin does not replace Confirmation of Payee, official registers, your own KYC and anti-money laundering checks, or professional advice. Live lookup results come from third-party public sources and may be incomplete or out of date. Payment timings are typical timings, not guarantees.
3. Use at your own risk
The site is provided free and “as is”, without any promise that it is error-free or always available. As far as the law allows, we are not liable for any loss that comes from using the site or relying on its results. Nothing in these terms limits any liability that the law doesn’t allow us to limit.
4. Fair use
Please don’t try to disrupt the site, run heavy automated traffic through it to third-party services, or use it for anything unlawful.
5. Other services
Live lookups and links use services run by others, including GLEIF, postcodes.io, Google Public DNS and Companies House. Their own terms apply.
6. Our name and logo
The SmugPuffin name, puffin logo and site design are ours. Data and software from others are used under their own licences, listed on the .
7. Changes
We may update these terms. If we do, we’ll change the date at the top. Using the site after a change means you accept the updated terms.
8. Law
These terms are governed by the law of England and Wales.
Questions? Email hello@smugpuffin.com.
About SmugPuffin
Built for the checks that come up constantly in onboarding, KYC and payments operations: is this IBAN the right length, does this BIC parse, does this sort code and account number actually pass the bank's own check.
Privacy
The checks on this page run in your browser. What you type into a checker is not sent to SmugPuffin, logged, or stored. You can confirm this yourself in your browser's network tab.
There are a few clearly marked exceptions, where something has to be looked up somewhere else. The email domain check sends only the part after the @ to Google's public DNS service. The live LEI and BIC lookups, and the bank and company name searches, send what you typed to GLEIF, the official LEI register, and the postcode check sends the postcode to postcodes.io. All of these only happen when you press their button.
There are no accounts. Your tile layout, theme and home timezone are saved only in this browser, on this computer. SmugPuffin never receives them. To use your layout on another computer, choose Customise layout then Use on another computer.
Read the full and .
What this is not
- It does not confirm an account exists, or who owns it. Only banks can do that (Confirmation of Payee).
- Most checks are format and check-digit validation. LEI, BIC and postcode have a live lookup, and the BIC lookup only finds banks that appear in GLEIF's BIC-to-LEI mapping.
- Payment arrival times are typical timings, not a guarantee. Banks set their own cut-offs.
Licence
The checks on this site are free, with no limit on how many times you use them. SmugPuffin Pro, coming soon, will be a downloadable version for bulk checking, for when you need to check a whole spreadsheet column at once. It will run on locked-down work computers since there's nothing to install.
Credits and licences
- Place and timezone search uses city data from GeoNames, licensed under CC BY 4.0, and country timezone data from the countries-and-timezones project (MIT), based on the IANA time zone database.
- Country timezone lists come from the countries-and-timezones package (MIT licence), based on the IANA time zone database.
- Live LEI and BIC lookups use the free GLEIF API. The BIC-to-LEI mapping has been developed by SWIFT and is used under the BIC/LEI Mapping Table License Agreement published on GLEIF’s website.
- Postcode checks use postcodes.io. Contains OS data © Crown copyright and database right; contains Royal Mail data © Royal Mail copyright and database right; source: Office for National Statistics licensed under the Open Government Licence.
- UK sort code checks follow the Vocalink modulus checking specification (v8‑50). IBAN, BIC, ISIN and LEI checks follow the ISO 13616, 9362, 6166 and 17442 standards.
- PDFs in Smart check are read with pdf.js by Mozilla (Apache License 2.0). Drag and drop uses SortableJS (MIT licence).
Need your IT team to approve this?
- Runs as a web page, so there is nothing to install and no admin rights needed.
- Checks run locally in the browser; nothing typed is stored. The only outbound requests are the button-triggered email domain check (domain only, to Google public DNS), the button-triggered LEI/BIC lookups and bank name search (to GLEIF), and the button-triggered postcode check (to postcodes.io). Smart check reads PDFs with Mozilla’s pdf.js, hosted on this site; the PDF itself is read on the computer and never uploaded. All code and libraries are served from smugpuffin.com, and the site’s security policy blocks connections to anywhere other than the services listed here.
- Sources: VocaLink modulus specification (v8‑50), ISO 6166/9362/17442 standards.