The phrase "a written undertaking" is correct and usable in written English.
It can be used in legal or formal contexts to refer to a document that outlines a commitment or promise made in writing.
Example: "The contractor provided a written undertaking to complete the project by the agreed deadline."
Alternatives: "a written commitment" or "a written agreement".
A private person needs no such protection against a written undertaking signed by himself.
The Russian foreign minister, Sergey Lavrov, demanded at the weekend that Nato give a written undertaking that the missiles will not be a threat to his country.
Reports over the weekend suggested that Mr Kerry had given the Palestinian Authority President, Mahmoud Abbas, a written undertaking that 1967 would form the starting point of talks.
He received Nick Clegg's support and on Friday he heard that his employer, ETDE, would reinstate him if he signed a written undertaking to abide by security requirements.
Ten days ago the master of the Quantock staghounds, Paddy Groves, was forced to apologise to the trust and give a written undertaking that the Quantock staghounds would not trespass in future.
Ashcroft himself had to provide a written undertaking in which he gave the Tory leader his "clear and unequivocal assurance" that he had decided to take up "permanent residence in the UK again before the end of this calendar year".
The report also found that when signing to claim for the daily allowance, members should give an explicit written undertaking that in doing so they are "acting on their personal honour".
The QC told the judge, Mr Justice Peter Smith: "This present litigation is born out of Sports Direct wanting, so far as it is lawfully entitled, to keep these commercial arrangements confidential under the terms of a written confidentiality undertaking".
Each candidate was asked to teach and then reflect on their lesson, undertake a written task to test both literacy skills and the ideas they had for 21st-century education.
Of the 366 patients who were screened for eligibility by the physician, 279 were excluded and 87 (23.8%) were recruited after a written informed consent was undertaken by the study staff.
Sometimes significant work can be undertaken without a written agreement.
