Your account is restricted. The app will not let you send, and the money already inside it is not moving. Support has said the same thing three times: the review team cannot share details, and someone will contact you. That was Monday. It is now Thursday. You have started reading the silence as accusation. It is not accusation. It is a payment services complaint that has not yet been written as one. This is the letter that writes it.
When to send it
Wait three business days first. Most freezes clear inside that window when the review team gets to the queue, and sending a formal letter into a queue that would have cleared anyway makes you look impatient rather than serious. Send the letter only if all three are true: more than three business days have passed since the freeze appeared, support has now replied with the same scripted line at least twice, and the firm has not sent you a written termination notice with a stated ground.
If the firm has sent a written termination notice with a specific reason, that is a different escalation and this letter is not the one for it. If your situation is a single transfer held for verification rather than a whole-account freeze, the verification-hold letter is closer. If you are not sure which of those you are looking at, start at the transfer-help hub.
The letter
Copy this into an email to the firm’s complaints address. That address is usually in the app’s help centre or in the footer of the firm’s website, and it usually starts with complaints@. Fill in the parts in square brackets.
Subject: Formal complaint - account frozen without explanation - account [ACCOUNT NUMBER]
To the Complaints Team,
I am making a formal complaint about my account, [ACCOUNT NUMBER],
which has been restricted since [DATE]. Since that date the following
transactions have been blocked:
- [INCOMING TRANSACTION 1] on [DATE], amount [AMOUNT].
- [OUTGOING TRANSACTION 1] on [DATE], amount [AMOUNT].
- [FURTHER BLOCKED ACTIVITY] on [DATES].
To your team I have already sent:
- [DOCUMENT 1] on [DATE], ticket [TICKET NUMBER].
- [FURTHER REPLIES] on [DATES], ticket [TICKET NUMBERS].
I am treating this as a payment-services complaint under Regulation
101 of the Payment Services Regulations 2017 (SI 2017/752). Under the
FCA rules for payment-services complaints (DISP 1.6.2AR), the firm
must send a final response within 15 business days of receipt of a
complaint. Please treat this email as the start of that clock.
Please confirm by [DATE, 5 BUSINESS DAYS FROM TODAY] either that the
restriction on the account will be lifted, or the specific ground on
which it will not be. If a final response is not sent within the
15-business-day window, I intend to refer the matter to the Financial
Ombudsman Service.
Regards,
[YOUR NAME]
[YOUR ACCOUNT REFERENCE]What to expect back
You will get one of two replies. The first is a substantive email inside 48 to 72 hours, either lifting the restriction or asking for one specific extra document or clarification. That is the usual pattern once a compliance officer sees the regulatory reference on the ticket. It is not a guarantee. The 15-business-day clock is on the firm, not on your money. But that is what most letters like this produce.
The second is silence, or another scripted reply. If the 15 business days pass with no substantive final response, you can refer the complaint to the 
Financial Ombudsman Service at no cost to you. This works when the firm holds a UK authorisation. Some apps you can use from the UK are actually authorised in another country. Before you write to any ombudsman, look at the bottom of the firm’s website. It will say something like “authorised by the Financial Conduct Authority” or “authorised by the National Bank of Belgium.” The right ombudsman follows from that.