1. Definition
The cost of funding divides the interest a bank pays by all the money it owes to third parties: its customers' deposits, what it borrows from other banks, from the Central Bank or on the market, its bond issues. In other words, its whole balance sheet except equity.
It says how much, on average over the year, each dinar the bank has at its disposal and does not own costs it.
It is also called the apparent cost of funding: «apparent», because it is computed from the published accounts, without the detail of the rates paid on each kind of funding. In French, it is called the coût des ressources, or coût apparent des ressources.
2. The measure
One formula, the same for every bank: interest expense for the half-year, annualised, divided by average third-party funding (total assets less equity) at the start and the end of the half-year.
Example, the bank with the lowest cost of funding: Attijari Bank, in the first half of 2026: each dinar of funding costs it 3.56% a year.
The lower the cost, the more margin the bank keeps between what it pays and what its loans and securities earn.
3. Why it matters
It depends mainly on how the bank gathers funds. Demand deposits pay little or nothing; savings and term deposits pay; refinancing from the Central Bank or the market costs more still.
It weighs on the interest margin. At equal lending rates, the bank that pays less for its funding keeps more income.
4. What it does not say
It does not say whether funding is stable. Cheap deposits can leave quickly; dearer funding can be longer and safer.
It does not separate the sources. It gives an average cost; it does not say what each one costs (deposits, borrowings, refinancing).
5. Where to read it in Tunisian financial statements
Interest paid is read in the income statement, item CH1, «interest expense and similar charges». Total assets and equity are read in the balance sheet, at the end of the half-year and at the end of the previous year.
The amounts are taken as published.
6. Three reading traps
First trap: over a half-year, the cost must be annualised. It is multiplied by 2 here, as an indication.
Second trap: the denominator takes the whole balance sheet except equity, including liabilities that cost nothing (provisions, accruals). The measured cost is therefore a little lower than the cost of interest-bearing funding alone; it compares banks, not a market rate.
Third trap: a fall can come from rates, not from the bank. When policy rates fall, all funding costs less; it is the gap between banks that informs.
7. Ranking of the 10 listed banks by cost of funding, first half of 2026
The banks are ranked from the highest value to the lowest, amounts in millions of dinars:
| Rank | Bank | Interest expense (TND m) | Average third-party funding (TND m) | Cost of funding, annualised |
|---|---|---|---|---|
| 1 | BNA | 668.7 | 22 841.6 | 5.85% |
| 2 | Amen Bank | 293.6 | 11 154.8 | 5.26% |
| 3 | BH Bank | 341.4 | 13 927.3 | 4.90% |
| 4 | STB | 341.3 | 14 298.5 | 4.77% |
| 5 | BT | 175.8 | 7 399.5 | 4.75% |
| 6 | ATB | 167.4 | 7 401.9 | 4.52% |
| 7 | UIB | 170.6 | 7 639.3 | 4.47% |
| 8 | UBCI | 105.4 | 5 339.9 | 3.95% |
| 9 | BIAT | 466.3 | 24 941.6 | 3.74% |
| 10 | Attijari Bank | 228.0 | 12 801.8 | 3.56% |
Out of scope: BTE (preferred dividend shares) and Wifak International Bank (an Islamic bank).
The cost of funding ranges from 3.56% to 5.85% a year depending on the bank. Across the 10 banks together, it reaches 4.63%.
Key points
- Cost of funding = interest expense (CH1), annualised, divided by average total assets less equity.
- It depends mainly on the share of demand deposits and on recourse to refinancing.
- It compares banks; a common movement often comes from rates.
Read also: net interest margin of a bank, what net banking income and net profit do not say, the method of the series.
Sources: interim individual financial statements at 30 June 2026 published with the Conseil du marché financier (CMF), notes included.