We’ve come across an issue with one of your Proprietary Codes being larger than the permitted value for the field. From your docs the list of codes is:
The ProprietaryBankTransactionCode property has two sub-properties: Issuer and Code. Issuer will always be set to Monzo, and the possible values for Code are listed below.

  • 3dsecure
  • account_interest
  • bacs
  • card_delivery
  • chaps
  • collections_settlement
  • emergency_cash
  • faster_payments
  • instalment_loan
  • ledger_adjustment
  • locked_money
  • mastercard
  • monzo_business_account_billing
  • monzo_flex
  • monzo_paid
  • overdraft
  • p2p_payment
  • payport_faster_payments
  • rbs_cheque
  • sepa
  • signup_referral
  • spread_the_cost
  • topup
  • uk_business_pot
  • uk_cash_deposits_paypoint
  • uk_retail_pot

However, we are receiving one which is not on the list (uk_cash_deposits_post_office_banking) which is length 36 and therefore outside the Max35Text from the OB Specs and is causing us issues. We are looking to truncate this as a quick fix but thought you guys may want to apply a fix.