Mutual fund orders can be rejected even after completing the payments by the RTA or by BSE StAR MF for the following reasons:

RTA Rejection

• • Cumulative PAN Level Amount Crossing EB Eligible Limit.
    The schemes in which Zerodha SIP or lumpsum investments have been suspended are as follows:
    

    Scheme Name	Circular	Investment Limit
    SBI Small Cap Fund	20210205-13	₹25,000/- per month
    Mirae Asset Emerging Bluechip Fund	20231009-8	₹25,000/- per month
    HDFC Defence Fund	20230608-1	₹10,000/- per month
    Nippon India Small Cap Fund	20230707-1	₹5 lakhs/- per day

    
    This occurs because AMCs may suspend lumpsum investments due to valuation and size constraints.
    
    To invest in such schemes, use AMC SIP. See What is the AMC SIP option on Coin web? Features such as instant pause and resume, instant modification, and step-up SIPs are disabled for AMC SIPs.
  • Aadhaar-EKYC Investment Amount Exceeds Rs. 50K  EKYC client. If the KYC flag as per the CVL KRA website ( https://www.cvlkra.com/ ) is marked as E-KYC, the maximum investment allowed is ₹50,000 per AMC. See Why did my mutual fund order on Coin exceeding Rs 50000 get rejected?
    
  • USA and CANADA Investors are not allowed to Invest.
    NRO clients from Canada and the USA cannot invest in a few mutual fund schemes. Additionally, if the KYC address mentioned on the KRA in Zerodha's records is in the USA or Canada, the orders can be rejected.
  • TPV invalid.
    When an account is opened with Zerodha, a Third Party Verification (TPV) is carried out for the bank accounts. Similarly, when an account is enabled on BSE STaR MF, the exchange does a TPV of the bank account and marks the bank account valid or invalid.
    If a fund transfer is made using a bank account that is marked invalid, the purchase order gets rejected from the exchange with the rejection reason as TPV Invalid. To learn more, see Why is the mutual fund order rejected with the error TPV Invalid?

BSE StAR MF rejection

• • FAILED: ORDER AMT IS LESS THAN MINIMUM SPECIFIED FOR SCHEME Minimum Amount Condition Failed:
    AMCs revise the minimum investment that is set for a particular scheme. Any order placed for less than the minimum investment will be rejected.
    
    Order Rejection from BSE after payment:
    
    
    • PAYMENT NOT INITIATED FROM CLIENT END
      This error is shown even if the payment is successfully made, but the order and payment mapping fail at the exchange level. In such cases, the refund is initiated within T+5 days.
      
      
    • FAILED: PASSWORD EXPIRED
      The order is not placed, but the payment is successfully made to the exchange. In such cases, the refund is initiated within T+5 days.
      
      
  • A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - The wait operation timed out.)
    
    Unable to access availability database 'BSEMFDB' because the database replica is not in the PRIMARY or SECONDARY role. Connections to an availability database is permitted only when the database replica is in the PRIMARY or SECONDARY role. Try the operation again later.
    
    This happens when there is a connectivity issue with the exchange. The order is not placed, but the payment is successfully made to the exchange. In such cases, the refund is initiated within T+5 days.
    
    
  • Payment received - order placement failed,
    FAILED: ORDER ENTRY NOT ALLOWED IN THE SCHEME CONTACT EXCHANGE ADMIN
    FAILED: ORDER ENTRY NOT ALLOWED IN THE SCHEME Subscription not allowed for requested scheme code.
    
    As per the BSE scheme master, the order can be placed, but the RTA rejects it as they receive communication from the AMC to halt the payments.