Overdrafts & 0% Promo Cards in a UK Debt Plan (Without Getting Caught Out)
Information & education only - not regulated financial advice.
This guide explains a planning approach based on the figures you enter. Your lender statements and terms are the source of truth.
Why this guide exists
A 0% deal is only “cheap” until the day it isn’t.
In the UK, a very common real-life setup looks like this:
an overdraft showing EAR (often high)
one or more credit cards on 0% purchase or balance transfer promos
then a standard APR after the promo ends
The trap is simple:
You build a plan that ignores the promo end date,
then your interest cost suddenly jumps - and your payoff date moves.
DebtRiot handles this properly (promo rate + promo months, then automatic switch to standard APR/EAR), and you can choose whether to prioritise expiring 0% deals - as a planning option, not advice.
Start here if you want to run your numbers privately: Debt Payoff Calculator
The core idea (simple and practical)
You have two competing priorities:
1) Expensive debt right now
Example: overdraft at 39.9% EAR.
This is often the highest interest cost every month.
2) Cheap debt that turns expensive soon
Example: card on 0% for 6 months, then 29.9% APR.
If you ignore (2), you can get hit by a “rate jump” and lose progress.
What does “prioritise expiring 0% deals” actually mean?
In DebtRiot, the setting “Prioritise debts with expiring 0% deals” is a planning rule:
ON: debts with 0% promos that end soon get pushed up the priority list before they become expensive
OFF: debts are prioritised only by the chosen strategy (Snowball, Avalanche, Hybrid, Cash Flow Index) using current costs
What counts as “expiring soon”?
“Expiring soon” = the promo ends within the next 3 months.
This is long enough to react and short enough to avoid overreacting.
The 3 UK scenarios you should plan for
Scenario A - 0% ends soon, overdraft is expensive
This is the most common “what do I hit first?” moment.
If the 0% ends in ≤ 3 months, it can make sense to prepare so you don’t face a sudden jump.
But overdrafts can bleed money every month.
So the best plan depends on:
balances
minimum payments
how much you can overpay each month
the promo end date
This is exactly why you want a comparison tool - not a one-size-fits-all rule.
Scenario B - multiple 0% cards end around the same time
This is where plans fail if they only optimise “today”.
If three cards flip from 0% → 29.9% within the same 8–12 weeks, you can get a “stacked rate jump.”
A good plan:
shows the timeline month-by-month
lets you model one-off cash (bonus, refund) in the month you expect it
updates instantly when you change the promo months
DebtRiot supports:
promo rate + promo months
snowflakes (one-off payments) by month
full PDF plan + CSV schedules when you choose
Scenario C - 0% is long, overdraft is the real fire
If your promo has 12–18 months left, it’s often reasonable to focus on the overdraft first - but only if your minimums are covered and the plan still works when the promo ends.
This is where a “hybrid” plan can outperform extremes.
How to enter 0% promos correctly (and avoid breaking your plan)
Step 1 - Enter the standard rate first
For a card, enter the standard APR you will pay after the promo ends.
For an overdraft, enter EAR.
Step 2 - Add promo rate + promo months (only if temporary)
Use promo fields only when the 0% (or low %) is temporary.
Promo rate: 0%
Promo months: how many months remain from next month onward
Important for consistency:
If you receive a 0% deal in the current month, and you want the promo to start next month in the simulation, keep your entry consistent across debts. (DebtRiot assumes promo logic applies from the next period in the plan - this keeps month boundaries clean.)
“0% forever” vs “0% promo”: what if APR is 0 but no promo fields?
If a debt has APR/EAR = 0 and you don’t enter promo months, treat it as:
0% with no end date (for planning).
If it’s actually temporary, enter promo months so your plan doesn’t lie to you later.
Example: What happens when a 0% deal ends
This is a planning illustration (not advice). Real charges depend on your lender’s terms and how interest is applied.
| Debt | Today | Promo ends | Rate after promo | Risk level |
|---|---|---|---|---|
| Card A (balance transfer) | 0% promo | In 2 months | 29.9% APR | High |
| Card B (purchase promo) | 0% promo | In 6 months | 24.9% APR | Medium |
| Overdraft | expensive now | — | 39.9% EAR | High |
Which strategy handles promos best?
This is where DebtRiot’s “compare 5 strategies” matters.
Avalanche
Great when your biggest cost debt is stable (e.g., overdraft is always expensive).
But promos introduce a moving target - today’s “highest rate” may not be tomorrow’s.
Snowball
Gives quick wins, can reduce the number of minimum payments quickly - which increases flexibility when a promo ends.
Not always the lowest interest overall.
Hybrid (two directions)
Hybrid strategies can be ideal when you have:
an overdraft bleeding interest now
a 0% card ending soon
…because they allow you to balance “today’s cost” with “future jump risk”.
Cash Flow Index
Useful if minimum payments are tight and you need to unlock cash flow earlier.
You can compare all of these using your exact minimum payments and promo months here: Debt Payoff Calculator
For the full methods explainer, link here: Debt Payoff Methods UK
The one-off payments that can “save” a promo ending (Snowflakes)
A “snowflake” is a one-off lump sum you can throw at debt:
bonus
tax refund
gift money
sold item
side gig month
DebtRiot lets you model this by month so you can see:
whether it prevents a promo rate jump from hurting you
how much faster your debt-free date becomes
If you need to build your monthly surplus first, use the free tool: Cash Stuffing Calculator
What to do next (simple flow)
Enter your overdraft and cards with correct rate types (EAR vs APR)
Add promo months for any 0% deals
Toggle “prioritise expiring 0%” ON/OFF to see how it changes the plan
Compare strategies (Snowball/Avalanche/Hybrid/CFI)
Preview the first 3 months free
Download the modern PDF + CSV schedules when you choose
Start: Build My Plan
If you’re struggling to cover essentials or minimum payments, you can get free, confidential help from StepChange or National Debtline.
FAQ
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Not always. It depends on your overdraft cost, balances, minimums, and how soon the promo ends. A good plan models both “today’s cost” and “the jump” so you can choose intentionally.
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Enter the standard APR you will pay after the promo ends. Then add promo rate (0%) and promo months. That way your plan stays realistic after the promo ends.
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In planning terms, “expiring soon” means the promo ends within a short window (commonly 3 months). The goal is to avoid getting surprised by a rate jump. (Use the calculator helper text and keep it consistent with the engine rule.)
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UK overdrafts usually show EAR. Credit cards and loans typically use APR. Comparing them correctly matters for payoff order.
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Yes. Add a snowflake payment in the month you expect it. The plan will show how it changes your payoff date and the order debts clear.
