Accounts at Companies House show Gillett's was charged by Royal Bank of Scotland after cash-flow was hit by spending on new stores and refits.
Sales director Mark Gillett said it was the first time RBS had enforced the covenant and that the retailer had faced a small charge as a result.
He added that a new deal had been reached with the bank and there was no danger of another breach of covenant.
The accounts showed turnover rose by 8% to £43.6m in the year ending October 2008, while pre-tax profits fell 2.3% to £1.2m.
The company bought eight new stores in the year covered by the accounts and has since grown its estate to 53.