McWhirter, from Edinburgh, was only caught after returning to the scene of one of his earlier false registrations in Aberdeen, where he was recognised by staff.
Police were then able to track him down due to his BMW Z4 convertible car which he used to travel between offices.
Around the same time, an "organised attack" on Revenue and Custom's computer systems, which showed around 350 tax credit application form requests had been received from addresses in Dundee and Campbeltown linked to McWhirter, triggered other alarms.
McWhirter presented letters to registrars at various offices throughout Scotland purporting to be from doctors confirming the births of children at home as well as marriage certificates in the names of 10 separate people who he claimed were the parents.
During the meetings he acted as if he was the man named on the marriage certificate while registering the birth, the court was told.
Fiscal depute Vicki Bell said he even told the Dundee Registrar he was having problems setting up the "home birthing pool" in his living room.
But in May 2015 in Aberdeen he registered two children's names and the following day at the same office he attempted to buy a copy of a marriage certificate for his brother Lockhart Brown, claiming his name was Luke Brown.
The registrar recognised him and heard him provide this different name.
Miss Bell said: "Four of the names used as claimants were traced and they advised they didn't make the claims.
"They had all, however, applied for the same job for front of house staff at a four-star hotel in Glasgow advertised on Gumtree on March 2015.
"The ad required a CV and a national insurance number.
"It transpired their details had been used to fraudulently claimed tax credits.
"It was then discovered that 14 claims for tax credits had been made by persons residing in Perth Road, Dundee, and in Campbeltown at flats related to the accused's company.
"In total the accused registered 22 false births for 26 children.
"During one he referred to problems with a home birthing pool and said his wife was a paediatric doctor.
"When he attended at Edinburgh registrars in June 2015 to register a birth he was seen using a silver or grey BMW car with a private plate.
"The motor car referred to led police to an address in Perth Road, Dundee, where the former co-accused opened the door.
"He provided full admissions stating he was in severe financial difficulty and needed money.
"He stated he considered the registration system in Scotland to be archaic and easy to create false registrations.
"His purpose had been to claim benefits pertaining to the child.
"During the search a large quantity of bank cards, computer equipment and approximately 50 birth certificates from the Republic of Ireland and documentation relating to claiming benefits were seized."
In Scotland a birth can be registered with a doctor's letter, compared to the rest of the UK where an NHS card number is provided for registration.
McWhirter pleaded guilty on indictment to a charge of fraud committed between June 1, 2014 and October 22, 2015 at addresses across Scotland.
McWhirter's solicitor John McLeod told the court his client was pleading guilty to the offence and was under no illusion that imprisonment was likely to be ''at the top of the list''.
Sentence was deferred until March 21.
