Antoinette Bradley

I have just spoken to an HMRC adviser about an underpayment of tax on my personal account for 23-24. They advised that the estimated income amount 'sent by my employer' was incorrect which contributed to the problem as my tax code was set using this incorrect (and too low) value. When I asked exactly what electronic return the employer sends to provide this estimated income figure, he could not give me a response so I don't think the employer does send this figure but would be good to confirm. Is the individual meant to update this on their personal tax account or should it be automatically updated based on the earnings patterns and data sent through on the RTI submissions throughout the year?