Interest on Capital and Interest on Drawings

Interest on Capital. Where the partnership deed provides for it, each partner is entitled to interest, at the agreed rate, on the capital he has invested in the firm — compensation for the opportunity cost of tying up his own money in the business, quite apart from his share of profit. Interest on capital is treated as an appropriation of profit, not as a business expense, and (unless the deed expressly states otherwise) is payable only out of available profit — if the firm makes a loss, no interest on capital is credited to the partners at all, because there is no profit left to appropriate.

Interest on Capital = Capital × Rate × Period (in months or a fraction of a year) ÷ 12

Where a partner introduces ADDITIONAL capital, or withdraws part of his capital PERMANENTLY, during the year, interest must be computed separately, time-period by time-period, on whatever capital balance actually stood during each period — never on the closing balance applied to the whole year, since that would overstate or understate the genuine interest actually earned.

Interest on Drawings. Symmetrically, where the deed provides for it, a partner who withdraws money for personal use during the year is charged interest on those drawings — since that money, once withdrawn, was no longer available for the firm to use in the business. Interest on drawings is a GAIN to the firm (credited in the Profit and Loss Appropriation Account), the mirror image of interest on capital.

Two calculation methods are used, depending on the pattern of drawings:

1. Average Period Method — used when a partner withdraws the SAME amount at REGULAR intervals throughout the year. Interest is computed once, on the TOTAL drawings, using the mathematically-equivalent AVERAGE period the money was, on average, unavailable to the firm:

Interest on Drawings = Total Drawings × Rate × Average Period ÷ 12

2. Product Method — used when drawings are of DIFFERENT amounts and/or made at IRREGULAR dates. Each individual withdrawal is multiplied by the exact number of months it remained outstanding until the accounting year closes, these "products" are added together, and interest for ONE month at the given annual rate is applied to that total: …