An escrow is:
an arrangement made under contractual provisions between transacting parties, whereby an independent trusted third party receives and disburses money or documents for the transacting parties, with the timing of such disbursement by the third party dependent on the fulfillment of contractually-agreed conditions by the transacting parties, or an account established by a broker, under the provisions of license law, for the purpose of holding funds on behalf of the broker's principal or some other person until the consummation or termination of a transaction; or, a trust account held in the borrower's name to pay obligations such as property taxes and insurance premiums.
Escrow generally refers to money held by a third-party on behalf of transacting parties. It is best known in the United States in the context of real estate (specifically in mortgages where the mortgage company establishes an escrow account to pay property tax and insurance during the term of the mortgage).
Escrow is an account separate from the mortgage account where deposit of funds occurs for payment of certain conditions that apply to the mortgage, usually property taxes and insurance. The escrow agent has the duty to properly account for the escrow funds and ensure that usage of funds is explicitly for the purpose intended. Since a mortgage lender is not willing to take the risk that a homeowner will not pay property tax, escrow is usually required under the mortgage terms.
Escrow payment is the common term referring, (in the US), to the portion of a mortgage payment that is designated to pay for real property taxes and hazard insurance. It is an amount "over and above" the principal and interest portion of a mortgage payment. Since the escrow payment is used to pay taxes and insurance, it is referred to as "T&I", while the mortgage payment consisting of principal and interest is called "P&I". The sum total of all elements is then referred to as "PITI", for "Principal, Interest, Tax, and Insurance". Some mortgage companies require customers to maintain an escrow account that pays the property taxes and hazard insurance. Others offer it as an option for customers. Some types of loans, most notably Federal Housing Administration (FHA) loans, require the lender to maintain an escrow account for the life of the loan.
Even with a fixed interest rate, monthly mortgage payments may change over the life of the loan due to changes in property taxes and insurance premiums. For instance, if a hazard insurance premium increases by $120.00 per year, the escrow payment will need to increase by $10.00 per month to account for this difference (in addition to collection for the resulting escrow shortage when the mortgage company paid $120.00 more for the hazard insurance premium than what was anticipated). By RESPA guidelines the escrow payment must be recomputed at least once every 12 months to account for increases in property taxes or insurance. This is called an escrow analysis.