What are the requirements for a Retirement Visa extension in Phetchaburi Province, Thailand?

What province ? This may actually get useful advice! Why do people post in Thailand groups without the province?

Each immigration should be the same, except they all have different ways of fixing problems.

Just provide everything you provided that first year. Year number two is no different, except for showing you bank balance you used never dropped below bt400,000 and was brought back up to bt800,000 at least two months before you apply for your next year extension.

Phetchaburi immigration will definitely require you to show the required funds in your bank account 2 months before you do your extension, also Phetchaburi immigration will require you to lodge a new TM 30 within 24 hours after you arrive back into Thailand. No need for a TM47 as this is only used for your 90 day report

well, some Immigrations run their own scheme and may ask for a seasoning of the 800.000.- THB for 3 months instead of the requirement that is listed in the police order under 2 months. The only way to avoid this kind of harassment is, you move to a different province 🫤

For the financials, I haven't heard of any offices that do it differently than what the official rules are:

You must have 800,000 in your account 2 months prior to the day you APPLY for your extension. Note that this is not 2 months before your current extension ends, it's 2 months from the day you apply for your next extension.

You then must keep the balance at 800,000 for 3 months AFTER you receive your extension.

The balance can never drop below 400,000 for even a moment the rest of the year.

A lease and TM30 should be plenty to show for your address. But as always the answer will be specific to your office.

The recommended advice is to go to your immigration office at least 1 week before you plan to apply for your extension and ask them for their handout of requirements for a retirement extension.