Director's Loan Calculator
Calculate S455 tax on overdrawn director's loans, Benefit in Kind at the 3.75% HMRC official rate, plan repayments to beat the 9-month deadline, and work out interest tax when lending to your company. All rates for 2025/26 tax year.
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How to Use This Calculator
Loan from Company tab
Enter the loan amount, the interest rate you pay (0% if interest-free), your company year-end date, and your tax band. The calculator shows your S455 tax liability (33.75% of the outstanding balance if not repaid within 9 months after year-end), the Benefit in Kind taxable amount, your BIK income tax, the employer's Class 1A NI, and the total annual cost. It also compares your position if you paid interest at the HMRC official rate (3.75%).
Repayment Planning tab
Enter your outstanding loan balance, planned monthly repayment, and company year-end. The calculator shows the 9-month S455 deadline, how many months you have, your projected balance at the deadline, and the S455 tax if not fully repaid. It generates a month-by-month repayment schedule and tells you the exact monthly repayment needed to clear the loan before the deadline.
Loan to Company tab
Enter the amount lent, interest rate, and your total income. The calculator shows your annual interest income, how much falls within your Personal Savings Allowance (£1,000 basic, £500 higher, £0 additional rate), the tax on interest, and your net interest received. It also shows the corporation tax relief the company gets on the interest paid.
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The Formulas
S455 Tax
Due: 9 months + 1 day after accounting period end
Refundable: 9 months + 1 day after the accounting period in which the loan is repaid
Benefit in Kind (BIK)
Your Tax = BIK × Your Marginal Income Tax Rate
Employer NI = BIK × 15% (Class 1A)
No BIK if loan stays below £10,000 at all times in the tax year
HMRC Official Rate for 2025/26 = 3.75%
Repayment Deadline
Example: Year-end 31 March 2026 → Deadline 1 January 2027
Monthly Repayment Needed = Loan Balance ÷ Months Until Deadline
Interest on Loan to Company
Taxable Interest = Annual Interest − Personal Savings Allowance
Tax = Taxable Interest × Marginal Tax Rate
PSA: £1,000 (basic rate) | £500 (higher rate) | £0 (additional rate)
Example
Sarah — Higher-rate taxpayer, £30,000 interest-free loan from her company
Sarah runs a limited company with a 31 March year-end. She has an interest-free director's loan of £30,000. She's a higher-rate taxpayer (40%).
S455 tax exposure
Annual BIK cost
Repayment plan
If Sarah paid interest at 3.75%
Sarah decides to repay £3,500/month to clear the loan before the S455 deadline, avoiding £10,125 in temporary tax. She accepts the £618.75 annual BIK cost while the loan is outstanding.