- involuntary bankruptcy
- involuntary investment
- involuntary lien
- involuntary saving
- Involuntary unemployment
- iodine colorimetry
- ion exchange
- iron taste
- iron turbidity
- irradiation
- irrational number
- irrecoverable
- irrecoverable debt
- irredeemable currency
- irredeemable stock
- irreversibility
- irreversible reaction
- irrevocable credit
- irrigation bond
- IS curve
- is management
- inward
- inward cargo
- inward charges
- inward clearance
- inward entry
- inward investment
- inward invoice
- inward port
- inwrap
- iodine test
- ionization chamber
- IOU money
- irradiated milk
- irradiated product
- irrational discount
- irredeemable bond
- irredeemables
- irrevocable debt
- irrevocable trust
- irritating substance
- ISIC
- isinglass
- isinglass industry
- island ban
- island display
- island position
- island site
- ISO container
- isobar
- isobarometric filler
- isobaths
- isocost curve
- isocost line
- isoelectric point
- isolate
- isolationism
- Isoquant
- isoquant curve
- isotherm
- issuance
- issue
- issue ad
- issue bank
- issue broker
- issue capital
- issue card
- Issue department
- issue house
- issue life
- issue market
- issue par
- issue premium
- issue price
- issue syndicate
- issue voucher
- Issued capital
- issued price
- issued stock
- IT number
- italian roast
- itayose
- itemized account
- iteration
- iterative method
- iterative process
- itinerant salesman
- J curve
- jack mackerel
- jacket
- jacking-up
- jam-jar
- jam-up
- Jamaican
- jansen clause
- january
- January barometer
- japan
- japanese
- Japanese herring