He said the vast bulk of texts he received related to minor administrative matter such as transport arrangements and diary changes.
He occasionally asked officials for information which was provided as an email or briefing note and the content of that was kept for the public record.
The Chief Archivist's report said although the Prime Minister was not fully aware of his obligations in handling public records, including texts, his management of them was "pragmatic."
"While this may occur for security reasons rather than record-keeping purposes, the Prime Minister's current approach does not indicate any wilful or negligent disposal of records without authority."
It said most texts were "transitory" which meant they would be disposed of.
"The Prime Minister's practice therefore appears likely to be compliant with the Act in relation to most text messages."
It said record-keeping advice to Mr Key was "inadequate" and had focused mainly on ministerial papers.
"The records, including text messages, that Minister create and receive when operating in their official capacities are public records and should be managed as such."
Archives NZ has since provided advice to the Prime Minister and other ministers to ensure they met the requirements of the Act.
The Chief Archivist started the review last December after a complaint by Green co-leader James Shaw who claimed Mr Key was breaching the Public Records Act by deleting his texts.
That was prompted by Mr Key's refusal to release many text messages between himself and blogger Cameron Slater on the grounds he had deleted them.
He said that was his standard practice with texts, partly because he got so many.
Mr Key had released some text messages with Mr Slater after the leak of findings in a report by Inspector-General of Intelligence and Security Cheryl Gwyn.
That report was into the handling of an OIA request by Mr Slater into whether Mr Goff was briefed about suspected Israeli spies in the aftermath of the Christchurch earthquake.
Mr Goff later admitted he leaked the findings and apologised.
Ms Gwyn's report found Mr Key's staff, Jason Ede, had passed on some information to Mr Slater prompting the OIA request.