Why the 6 months before you apply are critical
When you submit a mortgage application in Belgium, the bank doesn't just look at your salary. It dives into your history. At least 3 months of bank statements are required, but many institutions ask for 6 and some up to 12 months.
In practice, that means that from the moment you're thinking about buying, every transfer, every overdraft, every new loan you take out can be analysed. During that period, the bank is looking for three things:
- Your financial stability (regular income, no major incident)
- Your savings capacity (the gap between what comes in and what goes out)
- Your banking behaviour (overdrafts, account management, late payments)
Even if you tick the "official" boxes (max 1/3 debt ratio, sufficient own funds), your application can be refused or saddled with a higher rate because of behaviour the bank considers risky. And you often won't even be told the exact reason for the refusal.
Before you get started, we recommend reading our guide on understanding your borrowing capacity and the method for approaching the banks the right way. Now, here are the 10 mistakes to absolutely avoid.
Mistake #1: opening a new loan just before
It's the classic mistake. You're preparing your property purchase, but in the meantime, your old car gives up. You sign a car loan, a lease or even a €5,000 consumer loan to cope. You've just torpedoed your application.
Every new loan is registered in the Central Individual Credit Register (CCP) of the National Bank of Belgium. The bank sees it immediately. Worse: the monthly payment of that new loan is added to your debt ratio, which must not exceed roughly 1/3 of your income.
✅ Best practice: no new loan in the 6 months before your application. For the car, wait, or use part of your savings (while keeping enough own funds). A business or personal lease counts too.
Mistake #2: changing jobs or resigning
You get a great offer and switch employers three months before your loan application. On paper, you even earn a bit more. But for the bank, it's a red flag.
Banks require job stability. Concretely: confirmed permanent contract, probation period validated, ideally at least 6 to 12 months of seniority with the same employer. A resignation or a recent change makes your application "unfinanceable" or pushes the decision back.
✅ Best practice: if you're planning a mortgage, wait until you're settled in your job before resigning. If you're self-employed, plan for 3 complete annual accounts. If you're thinking about resigning to start your own thing, do it after signing the notarial deed — not before.
Mistake #3: leaving your account in overdraft
You have an authorised overdraft facility of €1,500 and you use it regularly. To you, it's normal — it's "authorised". To the bank, it's a very negative signal.
An account regularly in the red, even within the authorised limit, indicates that you're living beyond your means. Your income isn't enough to cover your spending. For the bank, adding a mortgage payment to an already stretched budget guarantees future default.
✅ Best practice: for the 3 to 6 months before your application, keep your current account always in positive territory, even at month-end. If you get paid on the 25th, aim to end the 24th of the following month with a positive balance. Learn how to decode your payslip to plan better.
Mistake #4: making suspicious transfers or receiving large sums
Your father transfers €20,000 to help you, with no documentation accompanying the transfer. You receive €8,000 in cash from a Facebook Marketplace sale. You make transfers to crypto trading platforms. These movements raise eyebrows.
Banks are subject to strict KYC (Know Your Customer) and anti-money-laundering obligations. Any unusual sum must be justified. Without supporting documents, your application drags on — or the sum is excluded from your contribution. Worse, it can trigger a report to the CTIF.
✅ Best practice: every significant movement must be traceable and justifiable. A family gift? Have a notarial deed of donation drawn up (or at least a signed letter). A sale? Keep the ad, the contract, the invoice. Avoid cash. As a reminder, money also needs to cover registration duties, so everything must be clean.
Mistake #5: not having stable savings
You save "when you can", sometimes €200, sometimes nothing, sometimes you take back €500 the following month. For the bank, that's not savings — it's just cashflow.
What the bank is looking for is a regular savings trajectory that proves you can handle a future monthly payment. If you put €300 aside every month for 12 months without touching it, that's reassuring. If your savings account yo-yos, it's a deal-breaker.
✅ Best practice: set up an automatic monthly transfer to a savings account, ideally the day after payday. Even €150/month tracked over 6 months is worth more than €1,000 paid in one go. Our guide saving for a property purchase details the strategy.
Mistake #6: late payments and registration with the CCP
A consumer loan instalment unpaid for 3 months. A Telenet bill in debt collection. An unrepaid revolving credit. It all ends up in the same file: the Central Individual Credit Register (CCP) of the National Bank.
As soon as a delay exceeds 3 months (or 3 instalments), you're listed in the negative section of the CCP. From there, it's almost always an automatic refusal. The listing stays active for 1 year after full repayment, and even longer in the history (up to 10 years depending on the situation).
✅ Best practice: before your application, consult your CCP file free of charge via the NBB website. If you appear in it, regularise immediately and wait for removal. Set up direct debits so you never miss a due date again.
Mistake #7: not playing the competition
You go to your usual bank, it offers you a rate, you sign. Classic mistake. You've probably just left several thousand euros on the table over the life of the loan.
On a €250,000 loan over 25 years, a 0.20% rate difference represents around €6,000 to €7,000 in extra interest. Banks know this: if you don't compare, you pay the "passive customer" tariff. Turning down a counter-offer — or not even asking for one — means giving up real negotiating room.
✅ Best practice: get at least 3 written offers (your bank + 2 others, or via a broker). Go back to your preferred bank with the best competing offer — nine times out of ten, it will match or improve. Our guide approaching the bank details the procedure.
Mistake #8: forgetting the outstanding balance insurance
The bank offers you an attractive rate. You sign. And then, in the office, they tell you "you just need to sign for the in-house outstanding balance insurance". You sign. You've just paid 30% too much.
Outstanding balance insurance (ASRD) repays the remaining capital in case of death. It's virtually mandatory and can represent €3,000 to €15,000 over the life of the loan depending on your age and health. Many banks impose their in-house contract to get the promised rate — but legally, you have the right to choose another insurer.
✅ Best practice: ask for 3 independent ASRD quotes before signing. Compare single premiums vs periodic premiums. Check the exclusions (sports, illnesses). In case of health issues, look into the BIM/MAF scheme and the Partyka Law, which caps surcharges.
Mistake #9: underestimating the extra costs
You're working out your budget: "The property is €300,000, I've got €30,000 down, everything's fine." Wrong. Extra costs can climb to 15% of the purchase price depending on the region.
Alongside the price of the property, you need to budget for: registration duties (3% in Wallonia, 2% in Flanders, up to 12.5% in Brussels), notary and deed fees (~2-3%), the bank's valuation (€300-500), application fees (often €500), and the mortgage registration (~1-1.5%).
✅ Best practice: simulate the total envelope from the start. For a €300,000 property in Brussels, plan for up to €40,000-45,000 in costs on top of the deposit on the property. Use our real estate deal analyzer to check consistency.
Mistake #10: signing the sale agreement without a suspensive condition
You find the house. The agent puts you under pressure: "sign the agreement quickly, or you'll lose the property". You sign without a suspensive loan clause. The bank refuses your loan two weeks later. You have to pay a 10% deposit penalty on the price.
The sale agreement in Belgium has the legal value of a final sale. Without a suspensive condition for obtaining the loan, if the bank refuses, you're legally obliged to buy — or to pay a breach indemnity (often 10% of the price). It's the most brutal sanction of the Belgian property journey.
✅ Best practice: NEVER sign a sale agreement without a clearly worded suspensive loan condition (amount, maximum rate, deadline to obtain it of 4 to 8 weeks). Our sale agreement checklist details the indispensable clauses.
The "all clear" checklist before your bank meeting
Before pushing the door of the bank (or your first meeting with a broker), run through what follows. If every box is ticked, your application starts with the best possible chances.
🎯 Check your situation
The Decisio quiz calculates your real borrowing capacity based on your profile, your income and your region.
If you're preparing a rental investment rather than a primary residence, also take a look at the property investment ROI calculator to check that the rent will cover your monthly payments.
Assume that as soon as you start seriously looking at properties, your bank account is being watched. Everything that happens in it will be used as an argument — for or against you. Switch to "clean file" mode 6 months in advance, not the day before.
In summary — the key points to remember
- Banks look at 3 to 12 months of bank statements before granting a mortgage
- No new loan in the 6 months before your application — no car, no lease, no consumer loan
- Job stability is mandatory: confirmed permanent contract, probation period over, no recent resignation
- Current account always positive, even within authorised overdraft — the bank reads it as over-indebtedness
- All significant movements must be traceable and justifiable (KYC, anti-money-laundering)
- Regular, documented savings are worth more than a single big transfer
- Check your file with the Central Individual Credit Register (CCP) at the NBB before anything else
- Compare at least 3 offers (banks + broker) and play the competition on both the rate AND the ASRD
- Plan for 10 to 15% in extra costs on top of the property price depending on the region
- NEVER sign a sale agreement without a suspensive condition for obtaining a loan