Illustrative example
A collection agency sues over a card balance from several years ago and relies on an email the debtor sent last year mentioning a payment plan. The debtor says the email was written only to stop the phone calls and never accepted that the balance was right.
An acknowledgment or promise contained in a writing signed by the party to be charged is the only competent evidence that takes an action out of the limitation periods in the CPLR. The section does not say what wording is enough, so everything turns on how that email reads - whether it acknowledges the debt or promises to pay it, as against discussing terms while disputing that anything is owed.
They agree a reduced lump sum in full and final settlement of the account, with the agency confirming in writing that it closes the file and makes no further contact with the debtor's employer.