We asked HMRC about the potential for digital systems to reduce costs. It told us that in 2023–24 about 69% of all its interactions with customers were digital and included taxpayers filing their Self Assessment returns online and using the HMRC app to check there Pay As You Earn code.51 HMRC also told us that about two thirds of the calls it receives are avoidable, as the customer could have carried out the transaction, or found out the information, by using digital services. HMRC said if it could divert or deflect that contact away to digital channels it could reduce its costs.52 Making Tax Digital