When asked by the Civil Government in 1881 what heraldry it used, the Mafra Town Council replied that it had no coat of arms "with any speciality or historical memory" and that it had only adopted the arms of King Manuel's reign, as he was the donor of the town's charter.
The Mafra municipality had made the national colours its own, displaying them in the 18th century on bells, official documents, and the coat of arms stone on the entrance of the Paços do Concelho building, now the Prof. Raúl de Almeida Municipal Museum.
In 1903, Major Guilherme dos Santos Ferreira designed a coat of arms that the City Council saw fit to approve, which was eventually endorsed by an Ordinance of 5 June, signed by King Carlos (D.G., 8 June 1903):
In a presentation to the Association of Archaeologists, transcribed in an article printed in O Século (7 January 1926) and entitled What should the coat of arms of the town of Mafra be?, Afonso Dornelas proposed a new coat of arms, featuring a deer, a reminder of the royal hunts in the Tapada (National Hunting Grounds of Mafra), and the bells of the Convent of Mafra:
“In blue, gold stag under two bells also in gold with red heads. Mural crown and strip at the base with the legend MAFRA".