By Lars Mucklejohn HSBC has pledged not to close any more of its branches until at least 2026 as regulators and politicians ramp up efforts to ensure access to cash and in-person banking services. The bank is due to tell its nearly 15m UK customers this week that it will extend a promise not to reduce its 327-strong branch network. HSBC is also planning to invest £50m this year to refresh its branches. UK lenders have closed more than 6,000 branches since 2015, according to consumer group Which?, as they look to cut operational costs and embrace the prevailing shift to online banking. HSBC has…