The Beatles legend - who released his debut solo LP 'McCartney' in 1970 and followed with 'McCartney II' a decade later - is set to announce the next record on Thursday (22.10.20).
A source told The Sun newspaper's Bizarre column: "Paul has been totally alone, with no producer or sound engineer, while making this record, just as he was for the previous two volumes.
“Obviously this time around recording in isolation wasn’t his choice.
“But it made complete sense for this album to be the third in the trilogy, particularly given the first came out five decades ago."
It's said Macca "had to get experimental" recording during the coronavirus lockdown, and the 'Hey Jude' hitmaker was happy to use whatever he could find around the house.
The insider added: "It’s been a true solo effort and he had to get experimental with what he used as instruments, hence the saucepan.
"He’s now gearing up to put it out in the coming weeks, with a global announcement due tomorrow.”
There have been some hints recently to tease the announcement, particularly on Spotify when a dice with three dots appears on the album covers when you listen to the first two albums in the trilogy.
On social media, there have been cryptic posts of things in sets of threes, while a new website domain - mccartneyiii.com - was registered over the summer.
Sir Paul - whose most recent solo effort was 'Egypt Station' in 2018 - previously said: "I’ve been able to write and get into music, starting songs, finishing songs.
“I’ve had a few little things to write and it’s given me the time to finish some songs that I hadn’t found the time to get around to.”
