The APC said the party's membership cards are not issued at its National Secretariat.
Media reports had indicated that Sheriff would be received formally into the party by national officials by 12pm on Thursday, April 26, 2018.
Daily Trust had quoted the APC's National Publicity Secretary, Bolaji Abdullahi, of saying, "The information I heard is that it will be tomorrow (Thursday) at 12pm."
However, in a new statement released Abdullahi, he has asked the former Borno governor to go register for the party in his ward as is custom for everybody.
According to The Punch, Abdullahi said the party's membership cards are not issued at its National Secretariat.
The statement read, "Our attention has been drawn to reports in some sections of the media that the former factional chairman of the Peoples Democratic Party, Senator Ali Modu Sheriff plans to defect to the All Progressives Congress today at the APC National Secretariat in Abuja.
"While we are aware of such intentions, we wish to restate our earlier position that anyone who wants to join the Party should do so at the ward level.
"We are happy to welcome new members to our party, but membership cards are not issued at the Party National Secretariat."
Sheriff was expected to be accepted into the party on Thursday alongside the PDP's 2015 gubernatorial candidate in Borno state, Gambo Lawan, who said the PDP has been hijacked by some people.
He said, "Yes, we have moved to the APC; I and former Governor Sheriff have left the PDP for the APC and there are reasons. Sheriff for instance is only going back home; he is the father of APC in Borno, he is a founding member of the party because he partook in taking the ANPP as one of the legacy parties that formed the APC.
"He only left the APC in 2015 when he was unfairly treated during the sharing of leadership positions when his candidate for the national secretary, Matawalli Kashim Imam was short-changed.
"So there is nothing new; Sheriff is the face of APC in Borno and the North East; he is the one who enthroned the incumbent governor and is behind the success story of many politicians.
"For me, I am not used to defection but was compelled to leave the PDP because it has been hijacked by some few people; the party has not reformed.
"And most importantly, politics is local; Borno is APC and it is for President Buhari. Our joining the party with millions of our supporters will strengthen it in Borno and environs."
According to sources that spoke to Daily Trust, Sheriff and Lawan recently met with President Muhammadu Buhari who directed the leadership of the APC to accept them into the party.
Sheriff was Borno state governor between 2003 and 2011 under the platform of the All Nigeria People's Party (ANPP) before he defected to the PDP in 2014.
In February 2016, he was installed as the party's National Working Committee (NWC) chairman in an acting capacity until he was removed during the party's 2016 National Convention three months later. Sheriff rejected the convention's decision, declaring that any other chairman was a 'counterfeit'.
In July 2017, a five man panel of the Supreme Court sacked Sheriff and installed Senator Ahmed Makarfi as the acting national chairman of the PDP before Uche Secondus was elected chairman at the party's 2017 convention.