People living near England's border with Scotland say they are angry that Covid-19 test and trace apps for the two nations are incompatible.
Users living in one nation and travelling to the other can only use one app at a time.
The Department for Health and Social Care (DHSC) said it was working on "a technical solution."
The Protect Scotland app launched on 10 September with the NHS Covid-19 app following last week.
Positive test results from one nation cannot be entered into the other nation's app and users say they can only receive alerts from one at a time.
In her daily briefing, First Minister Nicola Sturgeon said the Scottish government was "working really hard" with the NHS in England and Northern Ireland "on linking up Protect Scotland with the apps in those countries to support people who travel to make these different apps interoperable."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here