First of all, you’re not alone in this, and there are steps you can take to protect and maintain your relationship with your little girl.
Legal Parental Responsibility (PR):
Since you're not on the birth certificate and not married to your ex, you don’t currently have Parental Responsibility. That limits your legal say in big decisions like where your daughter lives. The good news is that you can apply for PR through the courts, and if you've been consistently involved in her life, it's very likely to be granted.
You can do this by applying for a Parental Responsibility Order or by making a Child Arrangements Order (CAO) application — you can actually do both in the same process.
Stopping or challenging the move:
If you think the move is not in your daughter’s best interests, you can apply for a Prohibited Steps Order (PSO) to stop her from moving until things are properly assessed by the court. Courts will look at what’s best for your daughter, including the impact on her relationship with you, and whether the move will disrupt her emotional stability and routine.
What the court considers:
The court’s priority is always the welfare of the child. If you’ve been seeing your daughter twice a week consistently, and she has a strong bond with you, the court will take that seriously. They will consider whether a move would negatively affect that relationship, especially at such a young age.
Maintaining the bond if she does move:
If the move ends up going ahead, you can work with the court to put in place a Child Arrangements Order that ensures regular and meaningful contact — e.g., weekends/holidays with you, video calls, possibly longer visits during half-terms/summer breaks. You may also want to ask for help covering travel costs, especially if you’re doing most of the travelling.
Get legal advice ASAP:
I’d strongly recommend speaking to a family solicitor (many offer free initial consultations) or contacting Families Need Fathers or Rights of Women (they advise dads too despite the name). You can also call Citizens Advice for guidance on the process.
You can apply to the court yourself without a solicitor if money is tight — look into a C100 form for the CAO and PSO. You’ll need to attend a MIAM (Mediation Information Assessment Meeting) first in most cases.
You clearly have your daughter’s best interests at heart, and whether or not your ex is moving for good reasons, you deserve a proper say in this. Getting legal PR is the first step to making that happen.