From improving the way we interact with customers to creating new delivery options, we are continually improving the customer experience. In 2022 this included further strengthening our customer service options to making it easier for consumers to select sustainable delivery options.
During the year we began using NPS to measure a variety of metrics internally, with the aim of switching to NPS to measure our strategic key performance indicators both internally and externally by 2023. NPS is a widely used metric and improvement tool that is utilised by many of our customers. The benefits of this change include more in-depth insights that are easier to translate into concrete actions, which will help us create greater value for customers through tailored customer journeys (see story below).
We continued to work on improving our service quality and operational excellence through our customer journey factory in 2022, which we established to advance the customer journeys of both our business customers and consumers.
We initiated nine journeys during the year, one of which focused on innovating and improving our parcel returns service. This included further implementing our 'Heen & Terug' label, which enables customers to use the same label for in and outbound parcels, and developing a home pick-up service for e-tailers. The customer journey team 'I manage returns' saw a steady improvement in NPS, with promoters particularly positive about the proximity of a PostNL retail point.
The customer journey factory is an ongoing process, and we believe it will continue to make a positive contribution to customer satisfaction scores in 2023.
Starting in 2023, third-party delivery companies will be able to drop off and collect parcels from our automated parcel lockers, many of which are available to consumers 24 hours a day, 7 days a week. We believe this step will make it even easier for customers and consumers to quickly, efficiently and sustainably collect and send goods. By year end we had over 500 parcel lockers across the Netherlands, and aim to increase this number to 1,500 by 2024 so that everyone has a parcel locker near to where they live.
In 2022 we saw a 65% increase in the number of parcels delivered or returned through the lockers, reflecting our growing coverage across the country and the value consumers place in them. We also recently developed the first PostNL parcel locker powered by solar panels, as we explore options to make them even more sustainable.
To make it even easier for consumers to access our parcel lockers, we have agreed to locate them in a range of supermarkets and other retail outlets, such as Jumbo and Plus Retail, across the Netherlands.
The number of consumers that connected with us digitally through a PostNL account continued to grow in 2022, resulting in 7.8 million unique accounts by year end. Customers satisfaction rates with the PostNL app were high, with almost 50% of app users giving it a 9 or 10 as an NPS score, which typically translates into loyal and enthusiastic customers. In the Apple and Play stores, the app was given a 4.5/5 by iOS users and 4/5 by Android users.
Additionally, 75% of consumers said in the app they were happy with the result of sending a parcel through PostNL, an increase of 1% point on 2021. During the year we also continued to add functionality across our digital accounts platform, including making delivery preferences available for both web and app accounts, which enables consumers to indicate a default preference and an away from home preference. We also continued to make the account more secure, introducing 2-factor authentication and more robust fraud prevention.
Our goal is always to provide high-quality delivery services, and while we have multiple policies and checks in place to safeguard that deliveries are successful, sometimes things do go wrong. Deliveries can be delayed, damaged or even lost. When something goes wrong we work with customers and consumers to find an appropriate solution as part of our customer care activities. And while the number of complaints relative to the huge volumes we deliver is small, we are constantly working to improve our service quality. One example is through the new PostNL Expertise Centre we opened in the Dutch city of Leeuwarden during 2022.
The Expertise Centre is there to help deal with any issues customers who contact us by chat, social media, complaint forums or phone may have. Some of the common topics dealt with by the team include queries about the location of a parcel or shipment, and questions about customs clearance costs.
In July we switched to using digital notifications only to inform receivers about a missed parcel delivery, either via email or through the PostNL app. This will enable us to share the most up-to-date information about the parcel's status with the recipient, will save around 70,000 kilos of paper per year, equivalent to over 200 maple trees, and will help us save costs.