The defendant as guarantor became bound upon notice within thirty days from maturity for all moneys due the plaintiff from the sale of wood paving blocks to the principal debtor, and under the admissions in the answer, and the master’s report, he is liable for the amount claimed unless relieved by the conduct of the plaintiff. Cumberland Glass Manuf. Co. v. Wheaton, 208 Mass. 425, and cases cited.
If by reason of a clerical error in bookkeeping the bill rendered to the principal debtor as- a statement of the final payment was very largely below the amount actually owing, the acceptance of the check in settlement, and the sending of the letter with the statement receipted, did not release it from liability for the unpaid balance. Grinnell v. Spink, 128 Mass. 25. It also is immaterial that the check was made by a third party. The statement, even if returned at its request to the maker and sender of the check, was open to explanation by extrinsic evidence. Hildreth v. O’Brien, 10 Allen, 104. Nor was it a discharge in writing of the debt or an accord and satisfaction within the doctrine of Guild v. Butler, 127 Mass. 386, 390. The notice to the defendant upon discovery of the mistake having been given within thirty days from default and the debt still, existing, there was a compliance with the terms of the guaranty. Cumberland Glass Manuf. Co. v. Wheaton, 208 Mass. 425.
But it is further- contended that as the debtor at the date of the notice of the mistake had no attachable property which he could reach for reimbursement, although at the time of sending the bill and check it had credits subject to trustee process, the defendant has been damnified by the plaintiff’s negligence, and hence is discharged. It is clear, however, from the master’s findings, *312that the principal debtor had become insolvent, and the defendant on whom rested the burden of proof, failed to show that when notified of the error in computation with a demand for payment, he then had lost any material pecuniary advantage against his principal which might have been enforced, if the original statement of the final indebtedness had been as represented. Cumberland Glass Manuf. Co. v. Wheaton, 208 Mass. 425. Welch v. Walsh, 177 Mass. 555.
The decree for the plaintiff must be affirmed with costs.
Ordered accordingly.'