Track a balance transfer and see when it actually pays off

A 0% APR balance transfer is one of the most useful tools in personal finance — and one of the easiest to mess up. The day the promo ends, your unpaid balance starts charging 24-29% APR retroactively in some cases. This walks you through setting up tracking so that doesn’t happen, and then using the BT Simulator to see what clearing the card actually does to your retirement number.

What you’ll learn

How to record a balance transfer with the post-promo APR
How to set the monthly payment that clears it before the cliff
How to read the urgency badges (red / amber / green)
How to use the BT Simulator to see the retirement ripple

Before you start

You’ll need the card already added on /Accounts as a Credit Card type. Have the promo paperwork handy — you need the start date, end date, transfer fee (usually 3-5%), and the post-promo APR. All of this is in the original offer or your latest statement.

What this isn’t for

The BT tracker is for 0% APR promotional periods, not ongoing-rate credit-card balances. If a card has no promo period — just regular monthly carrying — track it on /Cards instead. /Cards is where the priority-tier math lives (which card to pay down first based on APR and minimum payments).

Step 1 — Add the balance transfer (3 min)

Open Balance Transfers from the left nav (under Money). Click Add balance transfer.

Fill in:

Card account — pick from the dropdown
Promo start date — the day the transfer landed on the card
Promo end date — the day 0% becomes the post-promo rate (check your statement)
Original balance transferred — the amount that moved over (not including the fee)
Transfer fee — usually 3-5% of the balance; GlidePath adds it to what you owe
Post-promo APR — the rate that kicks in the day after the promo ends

[Screenshot: /BalanceTransfers Add form with the Acme household’s “Citi Diamond 18mo” promo filled in]

Save. You’ll now see your transfer in the table, with three things calculated automatically: months remaining, monthly amount needed to clear, and the urgency badge.

Try it: Open /BalanceTransfers ↗

Step 2 — Read the urgency badges (1 min)

The badge color is the single most important signal on the page:

Green — on pace to clear before the promo ends at your current monthly payment
Amber — pace is slipping; if you don’t change something, you’ll have a balance when the promo ends
Red — you’re not going to clear it in time at the current pace; act now

The badges update every time you snapshot balances on /MonthlyClose. So if you accidentally underpaid one month, the next snapshot will move you from green to amber.

[Screenshot: BalanceTransfers table showing one green, one amber, and one red badge with the Acme demo data]

Step 3 — Set the monthly clear pace (2 min)

Below the table, GlidePath shows the monthly amount needed to clear in plain English: “Pay $283/month for the next 11 months to clear before the rate snaps back.”

If that’s more than you can afford, you have three options, in order of preference:

Pay what you can each month, then pay the remainder before the promo ends. Often easiest if you have a tax refund or bonus coming.
Transfer the remaining balance to a new 0% promo card before the current one expires. Most people can get one.
Accept the post-promo rate on the remaining balance and prioritize paying it off on /Cards.

GlidePath doesn’t make this decision for you — it just shows you the math so you know which option is real.

Step 4 — Use the Simulator to see the retirement ripple (2 min)

This is where the feature does something nobody else does. Below the BT table, every active transfer has an inline panel called “What if I cleared this and put the dollars in retirement?”

It shows three live numbers:

Tax savings this year — at your marginal bracket from /Retirement
Future value at retirement — the freed-up dollars compounded
Change in Monte Carlo success probability — how much your plan’s odds of lasting improve

[Screenshot: BT Simulator inline panel with the three numbers visible for the Acme household]

You’re not just looking at a payoff number anymore. You’re looking at how clearing this card ripples through your retirement plan. For some people the answer is “clearing this card faster is worth $30K of retirement income in 23 years.” That’s a number that changes behavior.

What just happened

You did three things:

Recorded the promo so the post-promo cliff can never sneak up on you. GlidePath will badge it red the moment your pace falls behind.
Saw the monthly amount needed to clear as a number you can put in your bill-pay schedule.
Got the retirement-cascade view — so you know whether to prioritize this card over, say, maxing your 401(k) this year.

This is the math the Plaid-linked apps (Mint, Simplifi, Monarch) can’t show you. Their bank feed doesn’t include promo end dates or post-promo APRs — they just see “balance went up, balance went down.”

Where to next

The cascading BT Simulator in depth — coming soon — every assumption explained
Cards priority tiers — which to pay first — coming soon — for the cards without promos
Avalanche vs Snowball vs Promo-aware — coming soon — the three payoff strategies side by side

Ask Glide about this

Try: “Should I take a balance transfer that has a 4% fee?” Glide will walk through how to compare the fee to the interest you’d otherwise pay.

Common pitfalls

Don’t forget the transfer fee. A “0% for 18 months” offer with a 4% fee on a $10,000 transfer costs $400 up front. GlidePath includes the fee in what you owe automatically, but it’s easy to compare offers without accounting for it.
The post-promo APR is what’s on the offer paper, not the card’s normal APR. They’re often different. Use the offer paper.
Some cards charge “deferred interest” — the killer. If the promo is technically “deferred interest” rather than true 0%, the bank charges all accrued interest from day one if you don’t clear the balance by the end date. Check the offer carefully; GlidePath assumes true 0% unless you tell it otherwise on the form.