Unjustified interest and costs on a loan: checking and disputing them

You can dispute interest or costs on a loan if the calculation is incorrect, a valid contractual basis is lacking or protective rules have been breached. Start with a breakdown per period and per cost item. Merely establishing that the loan is expensive does not yet prove that you are entitled to a refund.

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A dispute may concern an increase in variable interest, repayments that were not processed, duplicate charges or an unclear final statement. With an old revolving credit, there may also be a dispute about the way the interest rate was adjusted in the past. With a private loan, the question is sometimes whether interest was agreed at all.

This blog helps you keep the different questions apart. This allows you to put together a targeted complaint to a bank, other lender or private lender and to assess better when legal assistance makes sense.

Which types of interest and costs appear on your statement?

Credit interest is the fee for the use of the borrowed money. Default interest relates to late payment. In addition, arrangement fees, administration fees, collection costs or a fee for early repayment may be charged. Whether an item is owed depends on the product, the arrangements and the applicable rules.

Ask for a statement in which these components are not lumped together. For your own records, note for each item the amount, the period, the percentage used and the contractual provision the provider relies on. A description such as “other costs” is too little to check whether it is correct.

Also note the distinction between the nominal interest rate and the annual percentage rate of charge (APR). The APR is intended to show the total cost of credit according to the calculation rules that apply to it. You cannot directly compare percentages that have different meanings and conclude from this, without further calculation, that too much interest has been paid.

Which costs appear on your statement?

Place each item from your statement in this table. You will immediately see which items have their own statutory limit and which you can dispute in a targeted way.

Item on the statement	What is it?	Where do you check this?	Common error
Nominal interest	The percentage charged on the outstanding balance	The agreement and any letters announcing changes	A change in rate that was never notified, or not in accordance with the variation clause
Effective annual interest rate	Interest including mandatory costs; this is how you compare products	The agreement and the pre-contractual information	A lower nominal rate that nevertheless turns out more expensive because of costs
Arrangement or brokerage fees	One-off costs when taking out the loan	The agreement; for consumer credit these count towards the credit fee	Costs kept outside the credit fee even though they materially belong to it
Management or administration fees	Periodic costs	Article 7:76(1) BW allows only two types of fee for consumer credit	A recurring item for which the contract provides no basis
Default interest	Interest on arrears	The contract; for consumer credit it may not exceed the ordinary credit fee	An increased “penalty rate” after a missed instalment
Collection costs	Extrajudicial costs	Article 6:96 BW and the Extrajudicial Collection Costs Decree (Besluit BIK); for a consumer, a reminder with a fourteen-day period is required first	Costs charged without a proper reminder
Early repayment penalty	Fee for early repayment	The agreement and the applicable consumer rules	A penalty that is not permitted at all for this type of product
Insurance premium	For example, payment protection insurance	Was it mandatory or voluntary?	A mandatory policy that was not included in the effective interest rate

Start with the original agreement

Request the signed agreement, the applicable general terms and conditions, the product information and later amendments. Check which interest rate applied at the outset, whether it was fixed or variable and which power to vary it was included. The terms of a new product on the website do not necessarily say anything about your old loan.

Then check whether the lender followed the agreed method. A fixed interest rate cannot be increased simply because market interest rates have risen. With variable interest, the scope for change depends on the arrangement and on statutory protection. The mere word “variable” does not yet answer every question about transparency and application.

For a private loan between natural persons who are both acting outside the course of a profession or business, Article 7:129c of the Dutch Civil Code (BW) provides that interest is only owed if it has been stipulated in writing. That is something different from interest for late payment. The statutory rules are set out in Book 7 BW, Title 2c.

How do you check the interest calculation?

A check starts with the balance that was actually outstanding. Record every drawdown and repayment on the correct date. Then the applicable percentage is used for each interest period. With changing balances or rates, a single simple multiplication over the original principal is often insufficient.

Ask which day-count method is used and when payments were processed in the accounts. How payments are allocated can also make a difference: repayment, interest and costs are different components. A payment that is rightly allocated first to costs or interest owed does not always reduce the principal by the full amount paid.

Finally, check how interest on interest is treated. That calculation may not be assumed without a legal basis, but nor is it prohibited in every situation. The contractual arrangements and statutory provisions must be applied to the correct period. A clear recalculation shows, step by step, where your balance differs from the lender’s.

Example of a balance-per-period check

An interest check starts with the balance, not with the interest rate. Calculate for each period: outstanding balance × (annual interest ÷ 12). If your result differs from the lender’s statement, the problem lies in the balance or the percentage, and that is exactly what you identify in your complaint. Fictitious example: revolving credit, balance €10,000 on 1 January, nominal annual interest 10%, monthly instalment €250, additional repayment of €2,000 on 15 March which the lender only processes in May.

Month	Opening balance	Interest according to you (balance × 10% ÷ 12)	Interest according to the lender	Repayment	Closing balance	Difference
January	€ 10,000.00	€ 83.33	€ 83.33	€ 166.67	€ 9,833.33	€ 0.00
February	€ 9,833.33	€ 81.94	€ 81.94	€ 168.06	€ 9,665.27	€ 0.00
March	€ 9,665.27	€ 80.54	€ 80.54	€ 169.46 + € 2,000 extra	€ 7,495.81	€ 0.00
April	€ 7,495.81	€ 62.47	€ 79.13 (still calculates using € 9,495.81)	€ 187.53	€ 7,308.28	€ 16.66 too much
May	€ 7,308.28	€ 60.90	€ 77.58	€ 189.10	€ 7,119.18	€ 16.68 too much
Interest overcharged over two months						€ 33.34

What if the variable interest on a revolving credit was too high?

With some revolving consumer credits, disputes have arisen about the relationship between the variable interest charged and the movement of a relevant market interest rate. This has led to rulings and compensation schemes. That does not mean that every borrower is automatically entitled to the same compensation.

Investigate your specific provider, product, contract period and interest arrangement. Request any compensation calculation and check which years, balances and assumptions were used. Check whether an amount has already been paid and whether you accepted a settlement agreement or a final release at that time.

A general online calculator is not always suitable for your product. Different assumptions can lead to large differences. A useful complaint therefore identifies which specific calculation step you consider incorrect. The rulings and knowledge resources of Kifid, the Dutch Financial Services Complaints Tribunal, can help you find relevant product disputes; whether they apply to your own agreement must be assessed separately.

Is there a maximum interest rate for loans?

Yes, for consumer credit. Article 7:76 of the Dutch Civil Code regulates this in two steps. Paragraph 2 provides that the maximum permitted credit fee is set by or pursuant to an order in council, to prevent lenders from taking on excessive risks. Paragraph 4 then prohibits the lender from charging, stipulating or accepting a higher credit fee, or from charging it at a time other than that permitted. That order in council is the Credit Fee Decree (Besluit kredietvergoeding); it links the maximum to the statutory interest rate plus a fixed number of percentage points. Because the statutory interest rate has changed over the years, that limit shifts accordingly.

Paragraph 1 is also important: the lender may only stipulate a fee that is owed on settlement in accordance with the payment arrangement, or that becomes owed if you remain in default after notice of default. Other fees are not permitted.

This makes the historical check important: a current limit may not simply be used for all the years of a loan. If your revolving credit has been running since 2009, it must be examined for each period which maximum applied at that time. Also check the scope: the rules apply to consumer credit, not to every business or private loan.

The name of a fee is not decisive either: costs that materially belong to the credit count towards the credit fee, even if they are called “administration fees” or “management fee”.

The name of a fee is not decisive either. Costs that materially belong to the credit may be relevant to the assessment of the total credit fee. A provider cannot simply circumvent protective rules by calling part of the fee administration costs.

A business loan, a mortgage and a private family loan do not necessarily fall under the same rules. So first have the product characterised. The statutory basis can be found in, among other provisions, Article 7:76 of the Dutch Civil Code and the Credit Fee Decree based on it. A conclusion that the limit has been exceeded then requires a calculation in accordance with the applicable rules, not merely a comparison of two separate percentages.

When can interest clauses be unfair?

In consumer contracts, general terms and conditions can be tested against the rules on unfair terms. Transparency, the balance of rights and obligations and the circumstances in which the agreement was concluded may be relevant. A unilateral power to vary therefore requires more investigation than just checking whether there is a signature.

Not every unfavourable clause is automatically unfair. Nor can it be assumed that a court will always simply replace an unclear interest clause with a percentage that seems reasonable. The legal consequences depend on the type of clause and the applicable rules.

Make clear in your complaint what the objection is: missing information, a non-transparent ground for variation, incorrect implementation or an impermissible contractual imbalance. The general Dutch rules on general terms and conditions are set out in Section 3 of Title 5, Book 6 BW. An assessment requires the complete terms and conditions and the context in which they were provided.

Which collection costs may a lender charge?

Collection costs are not the same as interest or legal costs. For a consumer, the statutory reminder requirements, among other things, are important before extrajudicial collection costs can become payable. The consumer must be given a proper opportunity to pay without those costs. The period is not simply calculated from the date at the top of the letter.

In addition, rules apply to the amount. Check on which principal the costs were calculated and whether the same work is being charged under several names. An administration fee cannot be stacked on top of collection costs without further assessment.

The Dutch central government explains the calculation of collection costs. For your case, the reminder, its receipt and the payments must also be checked. Also read our explanation of unjustifiably high collection costs. An error in the costs does not in itself mean that the principal borrowed lapses.

May the lender charge an additional penalty after arrears?

A penalty or increased interest rate must have a valid legal basis. Check which event triggers the fee and whether it has occurred. Also check whether the same loss is being charged in a way that conflicts with the contract or with protective rules.

In the case of a contractual penalty, you may in certain circumstances ask the court to reduce it. That does not happen automatically as soon as the amount feels high. The statutory standard and the circumstances must be substantiated. For consumer clauses, an unfairness test may also apply, with legal consequences different from an ordinary reduction.

So distinguish between three objections: the penalty was not agreed, the conditions for it to be owed are not met, or the clause itself is legally open to challenge. A letter that only states that you consider the penalty unreasonable often does not sufficiently show those possible grounds.

What if repayments are missing from the statement?

Find the payment on your bank statement and note the date, amount, receiving account and payment reference. Ask how the lender booked the payment. An incorrect reference can cause administrative delay, but it does not mean that money received may be ignored.

Also check payments made through a debt collection agency, bailiff or new creditor. Sometimes several sets of accounts end up running side by side. In that case, ask for a reconciliation between the old balance, the transfer, payments received and new costs. An assignment of the claim does not undo earlier repayments.

Keep original bank statements and correspondence. A spreadsheet you have made yourself supports the overview, but the underlying proof of payment remains important. If the principal remains too high because of an error, this may have a knock-on effect on interest calculated later. So, where necessary, ask for correction of the entire subsequent course of the account and not just for deduction of one payment.

Practical example: an incorrect balance causes additional interest

A consumer makes an additional repayment of €2,000 on a loan. The repayment has not been processed on the next statement. The lender continues to charge interest on the old balance and later also charges costs because, according to its records, a monthly payment is missing.

The first step is to compare the proof of payment with the receiving account and the booking details. Then it is calculated which balance should have applied on which date. If the processing was incorrect, it must be examined which interest items and subsequent steps have also become incorrect as a result.

This fictitious example concerns an administrative error, not necessarily an invalid interest agreement. That distinction is important: a targeted request for correction can be quicker and clearer than a broad complaint that the entire loan is unlawful. So enclose your own reconstruction and ask for a substantive response for each disputed item.

How do you write a good complaint about interest or costs?

Start with the loan number, the period concerned and your specific objection. Then describe which arrangement you believe applies and where the calculation deviates from it. Enclose an overview and supporting documents. Ask for correction, recalculation and, where necessary, repayment of a specified amount.

If information is still missing, identify it precisely. A clearly defined request for information is easier to verify than a demand to receive all data ever held:

Ask for a written position and information about the internal complaints procedure. Note when you complained and when a final response is due. A complaint does not automatically suspend your payment obligations or procedural time limits. So discuss separately how disputed and undisputed amounts will be dealt with during the investigation.

Should you keep paying while you dispute the interest?

Stopping all payments on your own initiative can lead to new arrears and costs. First examine which part of the obligation is actually in dispute and whether there is a legal ground for suspension or set-off. That is not the same as the mere fact that you have submitted a complaint.

Sometimes payment under express reservation can be practical, for example to prevent further escalation while a statement is being investigated. The wording and circumstances are relevant; a reservation does not automatically resolve all legal questions. Where necessary, ask in writing for a temporary arrangement for the disputed part.

If the entire loan has been called in, that step also requires separate attention. See a lender that calls in the loan. With a BKR credit registration, its accuracy and the balancing of interests must also be examined separately. An interest dispute does not automatically prove that every credit registration is incorrect.

Kifid or the courts: which route is available?

With a complaint about a financial service provider, the internal complaints procedure usually has to be completed first. After that, Kifid may be a possible route if the provider, the product and the complainant fall within the applicable rules. Not every business credit dispute can be dealt with there.

Check the time limits for submission and the nature of the procedure in good time. A settlement or binding decision may affect further options. So do not submit the same dispute in different places at the same time without an assessment. Our explanation of the Kifid procedure provides further guidance.

In court proceedings, the size of the claim, the nature of the claim and the supporting evidence are relevant, among other things. Have the costs weighed against the financial interest. A small calculation error often calls for a different approach from an incorrect interest clause that has had an effect for years or a substantial disputed final statement.

Watch out for limitation periods and earlier arrangements

A possible claim for repayment or damages can become time-barred. Which period applies and when it begins depends on the legal basis and the circumstances. Do not assume a single universal period for all interest cases. A recently discovered discrepancy does not automatically mean that all historical amounts can still be claimed.

Also check earlier compensation offers. Did you only receive money, or did you also sign an arrangement with a final release? Which products and periods did it cover? An offer may be attractive, but it is wise first to understand which rights you may be giving up by accepting it.

Keep older statements for as long as a dispute is ongoing. A lender may have information that you can no longer see in your online banking environment. Request missing documents in good time and discuss whether a targeted act to interrupt the limitation period is needed. Negotiating alone is not a reliable substitute for monitoring deadlines.

Do you have doubts about interest or costs? Read about our approach to a dispute with your lender.

Frequently asked questions about excessive interest and credit costs

Can I reclaim interest because my loan is more expensive than a new loan?

Not for that reason alone. Differences may result from the product, the period and the arrangements. For a refund, a legal or arithmetical ground must be established, such as incorrect application of the contract.

Does everyone with a revolving credit receive compensation?

No. The provider, product, period, interest arrangement and any earlier settlement are relevant. Check whether a specific scheme or ruling applies to you before you expect an amount.

May a private lender add interest afterwards?

That depends on the arrangements and the applicable rules. For a loan between natural persons who are both acting privately, credit interest requires a written stipulation. Default interest is a separate question.

Does the loan lapse if the collection costs are incorrect?

Not automatically. The principal, interest and costs each have their own legal basis. A justified challenge to the costs may go hand in hand with an obligation to repay the amount borrowed.

May I deduct disputed interest from my monthly payment myself?

Do not do so without an assessment of your rights and the consequences. An unfounded deduction can cause arrears. Ask for an arrangement or have suspension and set-off assessed legally.

Which documents are needed for an interest check?

The agreement, the applicable terms and conditions, interest rate notices, the complete course of the balance, proof of payment and earlier complaints or compensation arrangements. The more complete the timeline, the better the difference can be explained and calculated.

Have your interest or costs dispute assessed

Do you suspect that a bank, lender or private lender is charging incorrect interest or costs? Gather the agreement and the statement and contact Arslan Advocaten. An assessment focuses on the correct legal basis, a verifiable calculation and an appropriate route for requesting correction or repayment.

Written by Onur Arslan, attorney at Arslan Advocaten and responsible within the firm for the financial practice: credit registrations, loans of money and disputes with lenders. Registered in the specialisation register of the Netherlands Bar (Nederlandse orde van advocaten) for employment law and personal injury. Substantively reviewed on 12 September 2026 against the statutory text on wetten.overheid.nl.

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