Royal Mail is trialing a Sunday delivery service to improve flexibility, as a result of increased demand from online orders.

In addition, it is set to open around one hundred offices on Sunday afternoons, for customers to pick up parcels and post. The pilot scheme will be offered at delivery offices with the highest parcel volumes in the UK, the BBC reports.

Royal Mail’s express delivery service, Parcelforce Worldwide, will also offer a Sunday service to retailers from June. It will be up to the retailer whether to offer this to customers. Rival delivery firms Hermes and DPD have already announced plans to deliver on Sundays.

Royal Mail chief executive Moya Greene said the company is exploring ways to improve its flexibility. “The support of the Communication Workers Union (CWU) has enabled us to respond quickly to a changing market,” she added.

Royal Mail was privatised last year, it reports its first annual results as a public company on Thursday.