You should always use a CG calculator when reporting to HMRC and never use the brokers annual report (unless very simple). If you trade with more than one broker, you should combine all the transactions before calculating gains – e.g. selling SWDA in your T212 account and buying SWDA the next day on another broker’s account will affect how gains are reported due to the HMRC 30-day share matching rule.
Here are some other CGT calculators. You can use these other calculators to double-check the results from this site. They should all be very similar (some apply rounding differently – HMRC suggest you don’t round any figures but leave the final rounding to them). Note that offshore funds (e.g. ETFs) may have Excess Reportable Income – especially accumulating ETFs – most broker reports and most calculator sites do not report ERI. This can result in Basic rate tax payers declaring a higher gain than they need to and thus paying more tax than they need to. Higher rate tax payers who don’t include ERI may unintentionally not pay enough tax (as dividend tax for them is higher than CGT at 24%).
AFAIK Fidelity are the only brokers to include ERI in their tax report. cgtcalc.co.uk and my ukcgt.xyz can assist with ERI calculations but ERI rates are very difficult to look up (many are missing – even from the KPMG ERI search site). Most people try to avoid holding accumulating ETFs in their GIA for this reason (note that some distributing ETFs may also pay a small ERI and some ETFs may pay ERI as interest rather than as dividends).
Here are some other sites which you can compare UKCGT.xyz results with:
cgtcalculator.com – GOOD – popular and well-trusted site – untick apply rounding for HMRC-compatible results. A different conversion tool is required for each broker.
lategenxer – OK – seems to give similar results for cgtcalculator.com type data. Untick Apply Rounding. Can test using UKCGT.xyz format with DIVIDENDS support so you can input ERI Dividends.
cgtcalc.co.uk – GOOD – similar results to cgtcalculator com when ERI unticked. Will try to calculate ERI. Produces very nice HMRC ready reports and a PDF for HMRC. Supports several brokers, inc. T212 and cgtcalculator.com format.
ctgcalc galloway – OK expects BUY or SELL (not B or S) in capitals and only one column at the end for costs. Gives similar results to cgtcalculator when apply rounding is ticked. IMPORTANT: May give incorrect results unless you refresh the browser page each time before you paste in your data. Accepts DIVIDEND entries for ERI.
Taxing 212 – ??? did not seem to parse three .csv files correctly.
UK Tax Calculator – ??? seemed to produce rubbish results.