While he was passed over as Vice-Chamberlain of the Household in 1692 in favor of his elder brother Peregrine, he was appointed Auditor of the Duchy of Cornwall that year as a reward for his services.
Bertie opposed the attainder of Sir John Fenwick in 1697; however, he escaped dismissal from his auditorship when other members of the family were put out of office that year.
He declined to stand for Stamford in 1698, the Berties having agreed with the other county family, the Cecils, henceforth to share the seat; his uncle Charles continued as MP.
Bertie's salary as a Gentleman Usher had been converted to a pension upon the death of Queen Mary, but he found it increasingly difficult to collect under the Whig administration, and was forced to appeal to Lord Oxford, the Treasurer, for assistance.
Upon his death in 1728, he left an estate in Liverpool to his brother Albemarle, and lands in Lincolnshire and Somerset and an interest in Sir Cleave More's waterworks at Bootle to charity.