A clear guide to magnetic character recognition (MICR): the technology, the fonts, what each part of the MICR line means and how it is used today.
Quick answer: Magnetic character recognition, properly called magnetic ink character recognition (MICR), is a technology that lets machines read characters printed in special magnetic ink. It is used on the bottom line of cheques (checks in the US) to show the bank routing or sort code, account number and cheque number. Readers detect the magnetic signal of each character, so cheques can be processed quickly and accurately.
Look at the bottom of any cheque and you will see a line of strange, blocky numbers and symbols. That is the MICR line. It may look old-fashioned, but it is the reason banks can process millions of cheques with very few errors.
This guide explains what magnetic character recognition is, how it works, the two main MICR fonts, how to read a MICR line in the US, UK and India, and why the technology still matters in a digital banking world.
In this article
- What is magnetic character recognition?
- How does MICR work?
- What are the MICR fonts?
- How do you read a MICR line?
- Where is magnetic character recognition used today?
- Can you print your own MICR cheques?
- What are the benefits and limits of MICR?
- Frequently Asked Questions
- Final Thoughts
What is magnetic character recognition?
Magnetic character recognition is a way for machines to read printed characters by sensing magnetism instead of only looking at the shape. The full name is magnetic ink character recognition, or MICR, pronounced “my-ker”.
The characters are printed with ink or toner that contains iron oxide. When a cheque passes through a reader, the ink is magnetised and a read head picks up a unique waveform for each character. Because the signal comes from the ink, stamps, signatures or marks written over the line do not confuse the reader.
MICR was developed in the 1950s by the Stanford Research Institute and General Electric for Bank of America, and the American Bankers Association adopted it as the standard for cheques in the late 1950s.
How does MICR work?
1. Printing
Banks or approved printers print the MICR line in magnetic ink using a special font, with exact sizes and spacing set by standards such as ISO 1004.
2. Magnetising
The reader passes the cheque over a magnet that charges the iron particles in the ink.
3. Reading
A read head measures the magnetic signal of each character as it moves past.
4. Matching
Software compares each waveform with the known patterns for the font and identifies the character.
5. Processing
The data is used to sort the cheque, route it to the right bank and post it to the right account.
Many modern systems also capture a picture of the cheque and use optical character recognition (OCR) alongside MICR for extra checks.
What are the MICR fonts?
| Font | Characters | Where used |
|---|---|---|
| E-13B | 14: digits 0 to 9 plus 4 special symbols (transit, on-us, amount, dash) | US, Canada, UK, India, Australia and many others |
| CMC-7 | 41: digits, letters and symbols, made of 7 vertical bars | France, Spain, Italy, parts of Latin America and elsewhere |
The four E-13B symbols tell the reader what each number group means. For example, the transit symbol marks the routing number, and the on-us symbol marks the account field.
How do you read a MICR line?
US checks
- Routing number: 9 digits, between two transit symbols, identifies the bank
- Account number: your account at that bank
- Check number: matches the number in the top corner
UK cheques
- Cheque serial number: 6 digits
- Sort code: 6 digits that identify the bank and branch
- Account number: usually 8 digits
Indian cheques
India uses a 9-digit MICR code that shows the city, bank and branch, followed by other fields such as the account and transaction code.
A new employee in the US is asked for a routing and account number. She looks at the MICR line on her checkbook: the first 9 digits between the transit symbols are her routing number, and the next group is her account number. She enters both on the payroll form in two minutes.
Where is magnetic character recognition used today?
- Cheque clearing: the main use, in banks and clearing centres
- Remote and mobile deposits: apps read the MICR line from the cheque image
- Business check printing: companies print payroll and supplier checks with MICR toner
- Deposit slips and payment coupons: some bills and slips include MICR lines
- Fraud prevention: the magnetic ink is hard to copy with normal printers
In the US, the Check 21 Act allowed banks to process images of checks instead of the paper, but the MICR line is still captured from the image. In the UK, all cheques now clear through the image-based system run by Pay.UK, which also reads the MICR data.
Can you print your own MICR cheques?
Businesses can print their own cheques if they use MICR toner or ink, approved cheque stock and software that places the MICR line in exactly the right position. Ordinary toner will not produce the magnetic signal, so cheques may be rejected or need manual handling, which can mean extra fees.
- Buy MICR toner made for your laser printer.
- Use security cheque paper with features such as watermarks.
- Use cheque software that follows your bank’s format.
- Print a test page and ask your bank to check it.
- Store blank stock and toner securely.
A business that writes 200 supplier checks a month switches from pre-printed checks to blank stock with MICR toner. It saves money on printing and can run several bank accounts from one stock of paper, after its bank approves a test sample.
Managing supplier payments well also helps your tax records. See our small business tax deductions checklist.
What are the benefits and limits of MICR?
Benefits
- Accuracy: very low read error rates
- Speed: high-speed sorters process thousands of cheques per minute
- Security: magnetic ink is harder to fake
- Readable through marks: stamps and signatures do not block the signal
Limits
- Cheque decline: fewer people use cheques as digital payments grow
- Special supplies: needs MICR ink and exact printing
- Not fraud-proof: criminals can still alter amounts or payees, so other checks are needed
Never share a photo of a full cheque online. The MICR line shows your bank and account details, which criminals can use for fraud.
Take out a cheque or a voided check and identify the three parts of the MICR line: bank code, account number and cheque number. Knowing them makes setting up payments faster and helps you spot errors.
Interested in other machine-readable codes? Read our guide to the quick response code (QR code).
Frequently Asked Questions
What does MICR stand for?
MICR stands for magnetic ink character recognition, the technology that reads magnetic numbers on cheques.
What is a MICR code on a cheque?
It is the line of numbers at the bottom showing the bank code, account number and cheque number. In India, the MICR code is a 9-digit bank branch code.
What font is used for MICR?
E-13B in the US, UK, Canada and India, and CMC-7 in parts of Europe and Latin America.
Is the MICR number the same as the routing number?
In the US, the routing number is one part of the MICR line, but the line also includes the account and check numbers.
Can I print MICR checks at home?
Yes, with MICR toner, approved cheque paper and correct software, but test with your bank first.
Is MICR still used?
Yes. Even with image clearing and mobile deposits, banks still read the MICR data to route cheques.
Final Thoughts
- Magnetic character recognition reads characters printed in magnetic ink.
- The MICR line on cheques holds the bank code, account number and cheque number.
- E-13B and CMC-7 are the two main MICR fonts.
- MICR is still used in image clearing and mobile deposits, so its accuracy still matters.