**Yes, 0% APR can be a bad idea—but under the circumstances you describe, taking the full 48 months can be sensible.** If the price is identical, there are no fees, and the interest rate stays at 0% throughout, you pay the same £1,500 while retaining access to the money for longer.

The main downsides are:

- **Contract terms and missed payments.** Confirm that the agreement really is 48 equal payments, with no final lump sum or deferred-interest condition. Check late-payment charges and whether missing a payment affects the 0% offer. Set up a Direct Debit and keep enough in the payment account. [MoneyHelper’s borrowing checklist](https://www.moneyhelper.org.uk/en/everyday-money/credit/do-you-need-to-borrow-money) covers these checks.
- **Future borrowing.** The application may involve a hard credit search, and the monthly repayment can count against affordability when you apply for another mortgage or remortgage. Several furniture plans add up. [Experian explains credit searches](https://www.experian.co.uk/consumer/guides/searches-and-credit-checks.html), and [MoneyHelper’s affordability calculator](https://www.moneyhelper.org.uk/en/homes/buying-a-home/mortgage-affordability-calculator) includes existing credit commitments.
- **Reduced flexibility if you overpay the mortgage.** You would still owe the furniture instalments, while the £1,500 would be tied up in your home. Accessing mortgage overpayments depends on your mortgage terms. Check overpayment limits and early repayment charges too. [MoneyHelper explains the trade-offs](https://www.moneyhelper.org.uk/en/homes/buying-a-home/should-you-pay-off-your-mortgage-early).
- **Spending the money twice.** Keeping £1,500 in your account can make it feel available for another purchase. Taking several apparently negligible monthly commitments can also make your budget less comfortable.

Your expectation of another 48 paydays is reasonable for budgeting, but employment over four years is uncertain. Include all the instalments when calculating how long your emergency fund would last.

A straightforward approach is to **take the 0% plan and earmark £1,500 in an interest-paying savings account**, separate from your emergency fund. You can fund the repayments from that pot and retain the interest. Compare the savings rate after any tax with your mortgage rate if you prefer to overpay the mortgage.

Given that you already have the cash and an adequate emergency fund, the longest term is financially attractive if those checks pass. Paying immediately buys simplicity; that can also be worth something to you.