Paste your trades (outside an ISA or pension). It applies HMRC's share matching rules, then works
out the gain and estimated tax for each tax year ending 5 April.
Free to use. For information only. Completely private, your data never leaves your device. Works offline.
Every buy and sell for each fund in the order HMRC processes them, with the
pool after each step. Click a row or a marker to see what it's matched with. Sales and purchases on the same day
are combined into one line, as HMRC treats them.
How this is worked out
Matching. Each sale is matched first with shares of the same fund bought on the same day, then with any
bought in the following 30 days (the bed and breakfasting rule), and only then with the average cost of the
Section 104 pool.
Costs. Quantity × price, plus brokerage on buys. Brokerage on sales is deducted from proceeds.
Allowance. £12,300 up to 2022/23, £6,000 in 2023/24, £3,000 from 2024/25. Same-year losses always come
off in full. Losses carried forward only bring gains down to the allowance, never below.
Rates. 10% / 20% for disposals before 30 October 2024, 18% / 24% from then on. In 2024/25 the losses
and allowance go against the higher-rate gains first.
Your income decides how much is taxed at the lower rate: whatever's left of the basic rate band after
your taxable income. Leave it blank and everything is taxed at the higher rate. Pension contributions and Gift
Aid extend the band; this doesn't model that.
Not covered. Accumulation funds: the reinvested income you're taxed on each year (shown on your annual
tax voucher) should be added to the cost of the holding, which cuts your gain. Equalisation payments on
first-year fund units also reduce cost. Add these as extra "Buy" rows with quantity 0 and the amount as price ×
1, or adjust manually.
This is an estimate to check your own figures against, not tax advice.