How should I respond to an informal rent increase that would be the second this year?

My landlord texted, "Rent will be £1,320 from November. Everything has gone up." Our rent became £1,200 in February, and the message arrived in mid-October. My partner wanted to change the standing order that evening so we wouldn't seem difficult.

This is an assured periodic private tenancy in England. We don't live with the landlord. I haven't received a completed rent-increase form or advice on the message, and I haven't agreed to the new amount. The extra £120 would be a stretch, but the timing puzzled me before I even started comparing nearby rents.

The [current government guidance](https://www.gov.uk/assured-periodic-tenancies-tenants/rent-increases) says increases for this tenancy type use Form 4A with at least two months' notice and can take effect only once a year. I want an adviser to check our February paperwork and this request rather than assume I have understood every detail.

How do I ask the landlord to explain the proper process while keeping the conversation workable? We may eventually have a real disagreement about the amount, but I don't want changing a payment instruction to become our answer to questions we haven't checked.