Bank of England daily
HMRC STD/GBP Monthly Average Rate · August 2023
STD units per £1 · Dobra · Saotome & Principe
Source · HMRC
What is the HMRC monthly average rate?
HMRC publishes official monthly average exchange rates for use in UK tax calculations. For August 2023, the STD/GBP rate is 28414.6000 — meaning £1 sterling buys 28414.6000 Dobra.
These rates are published on the penultimate Thursday of each month and apply to the following month. They are the standard reference for HMRC-compliant tax reporting, including capital gains tax on the disposal of foreign assets.
To convert a STD amount to GBP using this rate: divide the STD amount by 28414.6000.
Using this rate for capital gains tax
If you acquired or disposed of a foreign asset in August 2023, this HMRC monthly average rate is one of two acceptable rate sources for your capital gains tax calculation.
The other is the Bank of England daily spot rate on the transaction date. HMRC permits either — but you must apply the same source consistently across acquisition and disposal within a single asset calculation.
The choice of rate source can make a meaningful difference to your CGT liability. We calculate both automatically and show the sterling gain under each.
Step-by-step: STD to GBP CGT calculation using the August 2023 rate
Convert acquisition cost
Take your original purchase price in STD. Divide by the HMRC rate for the month of acquisition to get the sterling cost.
Convert disposal proceeds
Take your sale price in STD. Divide by the HMRC rate for the month of disposal — which may be this rate if you sold in August 2023.
Calculate the gain
Subtract the sterling acquisition cost from the sterling disposal proceeds. The difference is your capital gain in GBP — reportable to HMRC.
Note on rate consistency: HMRC requires you to use the same rate source (monthly average or daily spot) for both acquisition and disposal within a single calculation. You cannot mix sources. We enforce this automatically and show the result under both sources side by side.
Other HMRC rates for August 2023
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Use this rate in your CGT calculation
Enter your disposal details and TealFX applies the August 2023 STD rate automatically — then compares it against the Bank of England spot rate so you can use the most favourable compliant figure.
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Frequently asked questions
What was the STD exchange rate in August 2023?
The HMRC official monthly average exchange rate for Dobra (STD) in August 2023 was 28414.6000 STD per £1 GBP. To convert a STD amount to sterling, divide by 28414.6000. For example, STD 100,000 ÷ 28414.6000 = £4.
What exchange rate do I use to report foreign income or capital gains to HMRC?
HMRC allows two approved rate sources: the HMRC monthly average exchange rate or the Bank of England daily spot rate (the 4pm fixing on the transaction date). Both are valid. For capital gains tax, using the more favourable rate can make a significant difference on large disposals. TealFX calculates your gain under both rates automatically.
Can I use the August 2023 HMRC monthly average rate for capital gains tax?
Yes. HMRC accepts the monthly average exchange rate as a valid method for converting foreign currency amounts to sterling for CGT purposes. You may use either the monthly average rate or the Bank of England daily spot rate — but must apply one source consistently across acquisition and disposal.
Where does HMRC publish official exchange rates?
HMRC publishes official monthly average exchange rates at trade-tariff.service.gov.uk. Rates are published on the penultimate Thursday of the prior month. TealFX imports these rates directly, so the figures on this page match HMRC's published data.