British households on standard energy tariffs are being urged to submit gas and electricity meter readings before the UK energy price cap increases on Wednesday. Multiple outlets report that the change takes effect as new unit rates for both electricity and gas apply, and that customers without smart meters may be charged based on estimates if they do not provide readings in time. The Guardian says an estimated 5.3 million households on standard tariffs lack smart meters and could be overcharged for some of June usage if they do not act. The Evening Standard reports the price cap rises by about 13%, citing an increase for a typical household from £1,641 to £1,862. The BBC also highlights a call for households to read their meters as prices rise, framing the issue around avoiding inaccurate billing. The broader coverage also notes that the price increase is occurring despite references to falling global oil and gas prices, with other reporting linking the change to wider concerns about household affordability and energy debt management.