BankIA / Guides
Financial guidesClear explanations, with examples you can check.
How a natillera (a Colombian savings circle) works, what the usury rate is, the difference between effective and nominal rates, how a CDT (term deposit) is calculated, and what to look for when choosing software for cooperatives. Each guide starts with the answer, shows the formula and links to the tool so you can run your own calculation.
- Answer first
- Formulas in plain view
- Worked examples
- No disguised advice
The most common questions, explained
Written for people who run savings groups, cooperatives and institutions, and for anyone who wants to understand their own numbers.
What a natillera is and how it works
A natillera (a Colombian savings circle) is a savings group with monthly installments, member loans and a year-end payout. How it works and its risks.
Open →How to keep a natillera’s accounts
What to record, how to calculate loan interest and how to split the funds at year-end without disputes. With a worked example.
Open →Usury rate in Colombia: what it is and how it is calculated
The usury rate is the legal interest cap in Colombia: 1.5 times the current bank interest rate. What it is, who certifies it and where to see the current one.
Open →Effective vs. nominal rate: differences and examples
What effective annual, nominal in-arrears and nominal in-advance rates are, how to convert them and why it matters when comparing loans and savings.
Open →How a CDT works: yield and withholding tax
What a CDT (term deposit) is, how the interest is calculated, what withholding tax is and how much is left net. With a worked example.
Open →Bylaws of a natillera: what they should include
The rules worth writing down before the first installment: contributions, loans, fines, withdrawals, distribution and closing. With a checklist to copy.
Open →How to distribute a natillera’s interest
The savings-month distribution explained with a step-by-step example: who receives how much, and what happens with events, loans and leftover cents.
Open →What the TRM is and how to use it to convert dollars
The TRM is Colombia’s official dollar exchange rate. What it is, who certifies it, how long it applies and how to convert dollars to pesos with it.
Open →How a loan installment is calculated (fixed installment)
A loan’s fixed installment step by step: the formula, how much is interest and how much principal, and how the installment and total cost change with the term.
Open →Natillera, cooperative or fund: differences
What sets a natillera, a savings and credit cooperative and an employee fund apart in Colombia, and which one fits depending on who you are.
Open →Income tax calendar for individuals
Deadlines to file your income tax return as an individual in Colombia based on the last two digits of your ID number, how they are calculated and who must file.
Open →What a credit analysis is and what it checks
What a lender analyzes before approving a loan: income, debts, repayment capacity, credit history and backing, with a worked example and the documents.
Open →How to choose software for a cooperative
Ten questions to evaluate any savings and credit cooperative software: exact money, audit, usury, data, branding and limits.
Open →Which guide are you missing?
Tell us what you would like to understand better and we will write a guide on it.