What is IFSC Code HDFC0003646?
IFSC or Indian Financial System Code is an alpha-numeric code that uniquely identifies a bank-branch participating in the NEFT system.
This is an 11 digit code with the first 4 alpha characters representing the bank, and the last 6 characters representing the branch.
The 5th character is 0 (zero).
IFSC is used by the NEFT system to identify the originating / destination banks / branches and also to route the messages appropriately to the concerned banks / branches.

IFSC is 11 alpha numeric characters code assigned by Reserve Bank of India to bank branches for facilitating online money / fund transfer using NEFT, RTGS or ECS between two bank accounts.

• The code consists of 11 Characters : (HDFC0003646) 11 alpha numeric characters code assigned by Reserve Bank of India to HDFC Bank Ltd Mahal Branch
  
• First 4 characters represent the entity (HDFC0003646)
  
• Fifth position has been defaulted with a '0' (Zero) for future use (ICIC0003646)
  
• Last 6 character denotes the branch identity (ICIC0003646)
  

What is MICR Code 440240017?
Magnetic ink character recognition (MICR) is a character recognition technology used primarily by the banking industry to facilitate the processing of cheques.
MICR characters are printed in special typefaces with a magnetic ink or toner, usually containing iron oxide. A special machine is used to read these characters, which can be easily read by humans too. The characters are usually printed on the bottom strip of cheque leaf.
This MICR code is used By RBI (Reserve bank Of India) clearing process to identify the branch and bank for clearing processes.
MICR 440240017 is 9 digits code printed on cheques to facilitate and expedite clearance of cheques in banking system.