A method and arrangement in a User Terminal (UT) for updating an operational parameter in the UT, the method comprising: to register, for at least one software module in the UT, a corresponding validator and/or a corresponding consistency verifier to a proxy module in the UT, wherein the validator is adapted to validate parameter syntax and wherein the consistency verifier is adapted to verify parameter consistency; to receive, from a Service Provider (SP), an operational parameter to be updated in the UT; and to check syntax validity and consistency of the received operational parameter which is based on each validator and/or each consistency verifier registered to the proxy module.