The service will be free until 30 May and will mean customers can have up to five parcels collected a day for free, on top of postage, with a service called Parcel Collect.
It usually costs 72p for a parcel or 60p for a return item. If an item does not have pre-paid postage, customers are able to pay for their postage online using click & drop available by visiting send.royalmail.com or via the Royal Mail app, Royal Mail said.
Lockdowns and stay-at-home orders have meant bumper years for postage and courier services. However, changes of rules over Christmas in England meant Royal Mail came under fire for a serious back up of parcels and letters. The service was also thrown into disarray in January when new restrictions came in due to the end of the Brexit transition period.
Watch: How England will leave lockdown
The free collection offer is the latest move to consolidate its place in the busy UK delivery market and echoes services offered by courier companies such as Hermés.
Customers must book a collection via Parcel Collect. When a postman or postwoman collects the parcel, the customer will receive an email notification that acts as proof of postage.
Nick Landon, chief commercial officer at Royal Mail, said: "This promotion is an opportunity for all consumers across the UK to try out this fantastic service free of charge.
"Parcel Collect is part of our commitment to continuously make our services more convenient as we reinvent the way we deliver to and from our customers.”
The news of the offer came as Royal Mail said it would pay a one-off final dividend after it reported a pick-up in letter volumes earlier this month.
It has maintained its profit outlook for the 2020/21 financial year, confirming its adjusted operating profit of £700m ($964m) for the year ending 28 March. Its final dividend will come out at 10 pence per share.
The group's stock had risen by almost 2% by mid-morning in London following the news.
Watch: Royal Mail axing 2,000 management jobs