Fixed Mortgage Rates: Safe at First, but Beware the Teaser Rate Trap
Tim Moneysaurus ยท 2026-07-26
"Fixed rate starting at 2.65%." A number like this is easy to fall in love with. The payment looks light, the dream home feels within reach. But there is one small word that often goes unread, namely for how long. A fixed rate on a commercial KPR (home loan / mortgage) almost always has a time limit, and what really determines how heavy a KPR is is what happens after that fixed period ends, not the sweet number at the start.
The situation right now
A fixed rate does indeed mean fixed. OJK affirms that a fixed rate does not change until maturity or the end of the loan term (OJK Sikapi, 20 July 2026). The problem is that on a non-subsidized KPR the word "fixed" usually only applies for the promo period, not until the loan is paid off. The pattern, as OJK explains, is a fixed rate for the first few years and then the following period uses a floating rate (OJK Sikapi, 20 July 2026). So a fixed rate is comfortable, but that comfort has an expiry date.
Reading the "FR" tiers on the brochure
Take a look at a bank's product page and you will find the rate numbers are always stamped with codes like "FR 1 Yr", "FR 3 Yr", or "FR 5 Yr". FR here stands for Fixed Rate, and the year number is how long that rate is locked. As an illustration, as of July 2026 the BTN Platinum KPR page lists regular promos such as "Fixed Rate 4.50% FR 1 Yr", "6.25% FR 3 Yr", and "7.50% FR 5 Yr", along with special per-developer promos that start from "2.65% FR 3 Yr" (BTN KPR Platinum, 20 July 2026). These numbers are promotional and period-bound, so treat them as an illustration, not a permanent rate. Always check the current numbers directly with the bank.
Notice the pattern. A lower rate is usually locked for a shorter time, while a slightly higher rate is locked for longer. This is no coincidence. The cheaper the teaser, the sooner you often enter the expensive phase. So "2.65%" that applies for 3 years is not necessarily cheaper in total than "7.50%" locked for 5 years, depending on how far the rate jumps after that.
There is also what is called the counter rate, namely a higher comparison figure. As an illustration, as of July 2026 the counter rate on the same page was recorded as "Fixed Rate 9.00% FR 1 Yr", "10.00% FR 3 Yr", and "10.25% FR 5 Yr" (BTN KPR Platinum, 20 July 2026). These numbers are also promotional and can change. What you need to grasp is that a single product can have several layers of rates at once, so make sure you know exactly which layer applies to you and for how long.
The most important question: what does it become afterwards
This is the question you must ask before signing, namely after the fixed period ends, what does my rate become. BTN states its condition verbatim, that is after the Fixed and Cap period ends a floating rate increase applies in line with the floating rate provisions in effect at that time (BTN KPR Platinum, 20 July 2026). The phrase "in effect at that time" is important, because it means you do not know the exact number right now; it follows the market conditions when your fixed period ends later.
How big is the jump? That depends on market conditions when your fixed period ends, so nothing can guarantee the number from now. You can get a hint from the non-promo numbers on the same brochure, namely the counter rate recorded in the range of 9% to 10.25% as above (BTN KPR Platinum, 20 July 2026), and a full floating rate usually moves higher still. Treat any number as an estimate that you must confirm with the bank at the akad (signing/closing). What is clear is that the jump from a teaser below 5% to a full double-digit rate is real, and your payment jumps right along with it.
An example of reading two offers
| What you see | What you need to ask | Why it matters |
|---|---|---|
| Fixed 2.65% for 3 years | In year 4, floating becomes what? | The cheap period is only 3 years, the rest can be double digit |
| Fixed 7.50% for 5 years | In year 6, floating becomes what? | More expensive at first, but longer certainty |
All the numbers above are illustrative and follow the promo rates in effect right now (BTN KPR Platinum, 20 July 2026). The point is the same, namely compare not just the fixed number, but how long it is locked and what it becomes afterwards.
Prepare yourself for transition day
The good news is you have years before entering the floating phase. Make use of that. Set aside the difference between the promo payment and the estimated floating payment into a cash reserve, so that when the rate rises you are not shocked. If possible, make a partial prepayment during the fixed period so that the loan principal is smaller before the rate climbs. And mark the fixed period's end date on your calendar, because the bank does not always remind you loudly.
So that this transition does not slip past you, you can record your payment and mark when the rate changes via WhatsApp to Moneysaurus. That way, the payment jump in year 4 or year 6 is something you anticipate well in advance, not a bitter surprise.
The one thing to take home
A fixed rate is a good friend at the start, but it has an expiry date. Do not judge a KPR by its teaser rate. Ask three things, namely how long the fixed rate applies, what it becomes afterwards, and whether you can still afford the payment at that floating rate. If the answer to the last question makes you hesitate, the offer is not necessarily as cheap as it looks. Judge a KPR by its structure and the total cost until it is paid off, not by the smallest number on the first line of the brochure.
Data sources: OJK Sikapi (types of interest rates) and the BTN KPR Platinum product page (Fixed Rate tiers and the conversion-to-floating provisions).